Have you tried Fortnite Creative mode? It can be as much of a virtual world as a FPS game engine. People are building islands for other types of games, for socializing, and just as art for art's sake.
You sure about that? It currently has the second-highest viewership on Twitch, topped only by League of Legends (which is surprisingly almost a decade old).
It was mostly a joke for people with school-aged kids. At least in my kids school, and what r/memes seems to reflect around the world, is they all say it's "trash" and Minecraft is the thing again. I think they all still play it, it's just cool to say it's not cool. However, a lot of them seem to have stopped buying V-bucks, at least to get skins.