Every edition of D&D is pretty much a reaction to that which came before it. Gonna ramble a bit.
Chainmail was a smaller skirmish game as a reaction to bigger fantasy wargames.
OD&D takes that a step further and into the personal, helped by the likes of Dave Arneson and Braunstein.
AD&D was a reaction to the lack of rules for things, the desire for more system complexity, etc.
Basic was two different attempts at making a game new players and kids could latch onto because AD&D was too complicated.
Second edition was quite a long period and itself had phases with different reactions. Like Dragonlance tried to make D&D “the novel” game happen. Trying to capture all the audiences with all the rules thinned the product line. Also idiosyncratic rules systems and a glut of competing products.
Third edition was created as a reaction to TSR’s failure in several ways. Have a rule for everything, but at least standardize the system somewhat. To deal with the rules glut and competing products they had the OGL which opened the door to thousands of products all being written to work with the same system. Two major failures were that the degree of ‘having rules for everything’ and things being incredibly customizable while balance was largely an afterthought (and with the magic item economy of sorts they had) meant no homogeneous experience, and the 3rd party products could just as easily turn someone off the hobby or onto a different variant splintering the market. Also you couldn’t really build a consistent computer game or platform cleanly with all this stuff sooo…
4e as a reaction to 3e was vastly streamlined, technically balanced, could get extremely tactically interesting… but traded off a lot of the things people who were not big on the miniatures based combat, the slog of same-ness between encounters and characters, etc. Also they were really hoping to take off with a virtual table-top and a subscription based model.
5e attempts to compromise a lot of that which came before. It definitely doesn’t have the options 3e/3.5 did. It isn’t quite as perfectly balanced as 4e is. It does sort of continue the trend towards attempting to eliminate the “variable” of the GM, but not the worst game about that. It’s not trying to sell the virtual table-top and subscriptions, but they also have a much much smaller staff and output rate. 3rd party stuff is possible, but not quite so ubiquitous. They do have a… “format” for pick up games, though it’s far from perfect, and if it’s not your kinda thing it’s probably best to avoid it. But it’s massively popular at the moment, the brand is big, twitch and services like roll20 kinda sorta let people interact with the hobby in new ways.
I think it’s inevitable that the 6e or whatever they choose to call it will be a reaction to those new mediums. I’m not sure how exactly they go about that, or if it’ll be any good, but I think it’s inevitable. Some kind of re-write to make it all more portable, probably some way to make it more bite-size. The adventure design in 5e for example seems to be balanced around a many-encounter day, but I think intentionally curbing the system towards adventure-league or one or two hour sessions is going to happen. Something someone can play a short youtube video about, or pick up and play different parts with different groups as necessary.