Ooh. Interesting question. Certainly hype is a major factor. It just snowballs. When everyone is talking about a thing, more people want to see what the fuss is all about.
The resurgence of D&D popularity probably helped a lot. (Thank you, Stranger Things).
You call 5E “dumbed down”, and maybe it is by tabletop standards. But by video game standards, incorporating all they did (with a little tweaking) and the way they did it is very far from dumb.
Other games might have pulled off similar levels of complexity, but not usually with all the high quality voiced cinematic dialogue and cut scenes.
The trend for AAA games has been making everything more and more accessible for ages. Larian didn’t strip it down to the bare minimum, they included as much as they could. The game doesn’t hold your hand much by telling you where to go and what to do. It rewards you for finding clever ways to approach things, and sometimes it rewards you for trying something really stupid just to see what happens.
It’s not a perfect game. I can think of some things I think they could have done better, but it’s a game that respects the player for figuring out how it works. And they’ve shown that there is actually a big market for that. I hope other developers will get the message.
Or maybe that’s all bollox, and it’s just because there’s sex.
