I think there are a lot of misconceptions about the rise and fall of particular editions.
True, and they have a lot more to do with business, marketing, and human nature than what was between the covers of the books.
The original game was dropped into the niche wargaming hobby, but also took off with some college kids, it made enough money, as a garage business, to fund printing one serious hard-back book in only three years (MM '77), and another each year after (PH 78, DMG 79). In the 80s, the game was accused of Satanism, as were a lot of things, (there was a whole minor later-day Salem thing going down in the 80s), and, like Heavy Metal, D&D benefited from that accusation with a flood of interest in the game from rebellious teenagers and shot to full-on fad status. It was also, as with so many meteoric phenoms, deftly 'stolen' from it's creator (or stolen from the usurper who stole it from Arneson, if you prefer that narrative).
That led to a new edition, that wasn't very new at all in a rules sense, and a new strategy of fiction-series tie-ins and floods of setting supplements that cashed in reasonable well on RPG trends in the 90s, except...
...CCGs happened, and the RPG hobby was all but killed off. TSR tried to make it up on novels and jump on the CCG hobby bandwagon, failed, and died.
So far, all of that had zero to do with the merits of the system (which was, even by the standards of it's contemporaries, to put it politely, 'lagging the industry').
CCGs fly higher, burn brighter and don't crash as hard as D&D did, but they still level off and, with much irony, the company that touched off the CCG craze white-knights the company that touched off the D&D craze, and with enthusiasm and accidental brilliance that only a fan could muster, makes D&D open source.
Even if that had flopped, it made D&D - at least, the d20 iteration of it - immortal. Again, that says nothing about the merits of d20 as a TTRPG system, the mere association with D&D, with the success/money of WotC, and being open-source make it a phenomenon that revives the tiny industry. ('Being open source' though is arguably 'something to do with the system,' so I'll conceded that nit.)
It was also a pretty mixed business move. Especially when WotC was acquired by Hasbro who had very, very different ideas about intellectual property, what constituted a 'core brand,' and how to flog revenue out of a niche product. So, Hasbro rolled 3.5 because, demonstrably, core-3 books sold better, so sell some more. But, at least it rolled a revised SRD to go with it, so the 3pps went along.
Not satisfied with sharing D&D's paltry revenue, however theoretically, with 3PPs, and with revenues never even flirting with what Hasbro considered 'core brand' worthy, WotC launched a desperate gamble, a new edition that'd sell on-line subscriptions to rival MMO income streams. They got a pile of money and a short time to make that happen. Oh, yeah, and kill the OGL and destroy our 3pp erstwhile partners while you're at it.
Shockingly, that plan didn't go well. The new RPG didn't sell at multiples of the entire industries revenue into the teeth of the worst recession since the great depression, and it's vaporware tools didn't bring in MMO-like revenue. To top it off, 3pps didn't swallow the GSL poison pill, and fans still had the immortal open-source d20 game to rally around. And, 'rally,' is putting it very politely.
D&D might have been doomed, but WotC comes up with another gamble, and this one's a lot safer. Consolidate the brand and stabilize it's image by hearkening to it's heyday. Cut production costs to virtually nothing and slow production schedules to a crawl (and even outsource said production after the core 3). Anything beyond recouping printing costs under that model is wild success.
The edition launches just as a boardgame renaissance is taking off, and succeeds,
wildly. (Though RPGs still don't rival boardgames, which don't rival CCGs, which don't rival MMOs, which is a layer-cake of irony, considering how closely-related the wargames D&D came out of were to boardgames, and that CCGs and, especially, MMOs both owe a huge debt to the D&D they ripped off.)
None of the above has anything to do with dying from an overabundance of material.
The failure of TSR did, but it was an over-abundance (relative to what the market would bear) of novels, spellfire cards, and dragon dice - especially novels, because the publishing business was unforgiving of over-production.
The failure of subsequent editions also mapped to an overabundance of material, even if it wasn't necessarily the cause of those failures.
And, while the actual design of the game mattered virtually nothing to all of the above, 'bloat' also maps to a design issue that D&D has always suffered from. D&D, with it's lists of classes, spells, races, weapons, magic item, and eventually skills & feats, expands player options by building on those lists. You want to keep the game interesting, you want to desperately try to appeal to an even slightly broader audience than the same geeks who have been playing since the 80s, you need to put out more material, there's just no other way to build on the system, because of that basic nature of its design.
But, when you do that, you degrade the system, complexity grows geometrically, new material eclipses old instead of supplementing, unintended synergies open up broken combos that obviate great swaths of alternatives, and the game just gets demonstrably worse - and, again ironically - presents /less/ real choice and appeal than it did before it was expanded to add choices and broaden appeal.
That's all true, and it's a game-design reason to roll rev, but it's not the story behind the 'failure' of each past edition, especially the most dramatic ones. Those are stories of business & market factors.
But, we're hobbyists deeply familiar with the arc of those systems (and often deeply invested in one of them), so we prefer the 'bloat' narrative, anyway. We think of the complexity of peak 3.5 and figure 5e is 'simpler' so it succeeded, but bloat may still kill it. But D&D has never been simple (nor is 5e the simplest
system of the lot, it's just not being built on much), and never been killed by the bloat, itself, because the system, itself, has never been a significant factor in its success or failure.