Ruin Explorer
Legend
So it seems WotC has an idea why it’s so popular. Are they right? Did they nail it or kinda set things up for success and took advantage of good things when they saw them? Or a bit of both? Or are they just lucky?
To me, based on the language around 5E at the start, and the playtesting, it looks like a significant amount of luck was involved. Like, I don't have a clear impression that they knew stuff like Critical Role was blowing up and designed the edition accordingly. I think the main goal, was to produce a somewhat evergreen (I don't think it'll actually last any longer than any other edition, FWIW) edition which took a sort of look over all of D&D, to try and get a lot of the best elements together, and thus have a maximally broad appeal. To do that, they needed to make an edition was more accessible, on a basic level, than really any of the previous edition-editions. It's more akin to RC D&D in complexity that any of 1E-4E.
And then because of stuff like Critical Role, and because younger people want social stuff, not just computer stuff, because they've got enough computer stuff, and because it feels like something it's okay to play with kids, and for kids to play (which I'm not sure all previous editions have, if only because of complexity), it's really taken off.
Once they got going, too, I think they've got a lot better at choosing their direction and what to do next and so on. I still think they're struggling with some stuff, like managing merchandised products - for example Wildemount's subclasses and spells are just completely unacceptably overpowered next to any other official 5E material, but I guess WotC didn't feel they could go "Nope, uh-uh, no way..." to that stuff, even though did that to non-overpowered stuff in Eberron. But was putting out a CR book smart? Definitely for both parties.