Here's something to ponder - if The Simpsons had started life as a full-fledged TV series from the beginning, rather than as a collection of shorter supporting segments on a comedy sketch show, then would Maggie still have been a part of it? That may seem like an odd question - after all, Maggie is every bit as iconic as any other member of the family, and would your typical Simpsons milieu really be the same without the sounds of her obsessive pacifier-sucking emitting from somewhere in the backdrop? But consider this - Maggie seldom gets to be more than just an orally-fixated runt supplying background noises. Episodes in which she plays a significant part in narrative progression are undeniably thin on the ground, which I suspect has to do with her being such a challenging character to build extended stories around. Maggie is a perpetual infant - that is her charm, but also her great limitation. Her non-stop pacifier cravings may supply her with her characteristic means of expression, but her need to keep the artificial teat clasped between her gums at all times also signifies an attachment to the status quo; an aversion to growth and development. All of the family are bound by some degree by the show's fundamental need to preserve the status quo, but Maggie is the one who offers by far the least scope for expansion, in that she (almost) never speaks, and she's severely limited in her ability to interact with other characters. I seem to recall that David Silverman actually said something along these lines when discussing the then-upcoming theatrical short The Longest Daycare, which gave Maggie a rare turn in the spotlight, only the quote in question now eludes me. If I remember correctly, he stated that they chose to focus on Maggie because her brand of pantomime humour is better suited to a four minute short than to a twenty-two minute episode. She's a character built for very short adventures, not longer-form narratives.
Episodes from earlier on in the series' run did make more of an effort to accommodate Maggie and her unique character traits. "Call of The Simpsons", for example, has that adorable, if rather baffling subplot which sees her getting lost in the wilderness and adopted by a family of grizzly bears. "Itchy & Scratchy & Marge" has her instigating a huge part of the narrative action with her repeated attempts to brutally injure Homer, while "A Streetcar Named Marge" gives her her own miniature arc in which she spearheads a mission to liberate a collection of confiscated pacifiers at a ridiculously authoritarian daycare. As the series went on, however, it seemed that the writers slowly started to lose interest in Maggie's place within the main family dynamic, relegating her increasingly to the same level as family pets Santa's Little Helper and Snowball II, in that she was often more of a prop than a character per se. Maggie still had her uses (most notoriously, she got to be the one to pull the trigger on Mr Burns in the series' much-publicised two-part mystery) but Season 5 onward saw her fade increasingly into the backdrop. There's a Season 11 episode, "Hello Gutter, Hello Fadder", where Homer explicitly refers to Maggie as "the forgotten Simpson", which was less a reflection of Homer's negligent parenting than an admission from the writing staff that they hadn't known what to do with her for yonks.
To ruminate on the question I posed earlier, I certainly wouldn't want any version of The Simpsons that didn't have room for Maggie. She's an ostensibly minor but very vital part of the family dynamic, with her non-verbal mannerisms providing a welcome contrast to wordiness of the rest of the clan. I love the fact that she's such a wild card and you can't often tell what she's thinking - depending on the circumstances, she can be either an oblivious innocent, a precocious whizz-kid, or even unnervingly dangerous. Maggie's the kind of character you underestimate at your own peril, as both Homer and Mr Burns can attest, and if the writing staff aren't interested in probing that amazing infant brain of hers, then that's their loss entirely.
"Babysitting Maggie" is the first Simpsons short to put Maggie at the centre, painting her as a happy-go-lucky tot who seems perpetually oblivious to the horrors of the world she inhabits - not least the cold indifference of her negligent older siblings, who have been tasked with watching her while their parents are out but, predictably, cannot pry their eyeballs away from the seduction of the chattering cyclops. At the mercy of such mean and inattentive souls, Maggie has no chance of survival, or at least she wouldn't if not for the cartoon physics holding her together. As Ullman shorts go, this is is actually one of the darker and more mean-spirited in tone, since it revolves around Maggie wandering around the house unattended and stumbling across deathtrap after deathtrap in her guileless pursuit of a butterfly. Miraculously, Maggie always survives, unshaken and unscathed, but not without enduring a ton of physical abuse that in a more realistic scenario would result in a dead baby or at the very least one with life-changing injuries. Bart and Lisa do not come across terribly well in this one, particularly Bart, who seems to have assumed the mentality of a domestic abuser, as evidenced in this exchange, where Bart produces a retort that seems more befitting of his tormentor Nelson Muntz:
Lisa: I think I heard a thud...
Bart: You'll hear another one if you don't shut your trap.
Sure, Bart and Lisa had a much more hands-on sibling rivalry back in the day, but there's something about seeing Bart subjugate his younger sister with the threat of physical violence that just rubs me the wrong way. But then "Babysittting Maggie" is an uncomfortable short all-round. It toys with our emotions, knowing all-too well how the sight of an infant in peril arouses our protective urges, every thud Maggie makes as she tumbles down the staircase being engineered to make us wince. Maggie never seems at all hurt or fazed by her non-stop misadventures, leading up to the final punchline, where Maggie's butterfly friend flies away, prompting her to erupt in tears and Bart to dismiss her as "such a baby". An appropriately callous conclusion to a pretty cold-hearted short, I suppose (honestly, the lack of comeuppance for Bart and Lisa is really annoying). I'd note that this kind of calamity without consequence was something that The Simpsons would move increasingly away from as it developed as a concept. (Remember how big a deal it was in the Season 2 episode "Bart The Daredevil" when Homer falls down a canyon and endures some seriously gruesome looking injuries?) There's also a tendency, one maintained all throughout the Ullman shorts, for Maggie to break the fourth wall at the end of skits. She certainly does stare directly into the camera and smile at the viewer a lot, which is her way of signalling that everything is a-okay (and hinting that, despite appearances, Maggie is actually the most canny and self-aware of the Simpsons brood). This was another gag that ultimately got axed as the show settled upon a less overtly cartoony approach.
"Babysitting Maggie" was effectively remade at the end of the Ullman shorts' run as a two-part story, "Maggie In Peril", which again involved Maggie wandering into all kinds of life-threatening danger while under the care of Bart and Lisa, who fail to realise that she's even slipped her playpen. By this stage, The Simpsons had sharped both in confidence and animation quality, so the peril could be staged a lot more dramatically, and Maggie herself doesn't undergo a fraction as much of a physical beating this time around.
Finally, "Babysitting Maggie" establishes that Maggie has something of an affinity for butterflies, so might we view it as a sort of precursor to The Longest Daycare, which involves Maggie befriending a butterfly within the walls of a highly impersonal daycare centre, and protecting it from obliteration at the hands of Baby Gerald? I see it almost as coming full cycle; both shorts entail the challenges of surviving, against the odds, in a world that blatantly doesn't care less, only whereas in "Babysitting Maggie", Maggie is the one who's been left helpless and alone, by The Longest Daycare she's grown savvy enough to comprehend the bleakness of her situation, and is using the skills at her disposal to defend a being even more defenceless than she. It seems as if Maggie is moving up in the world, and figuring out what she can do to make it a marginally more bearable place.