It's core idea was/is implemented in way better ways - Dreams was a great step, Fortnite & Roblox are currently trying to do the same thing, and hell, even old GTA San Andreas and Garry's mod were more of a metaverse than Horizon Worlds ever came to be.
On the concept of fun - of course it doesn't understand it. The tech scene has move from the fun, hacker ways into the dark pit of standardisation, processes, bureaucracy and average. Creativity gets sapped out of it to conform to a kafkaesque mind of your average stakeholder. Designer's and developer's opinions get overridden by glorified paper pushers.
You can see it happen in every startup, and the valley is the same - to conform to the largest possible market, as it grows, everything has to be averaged out and greyed out - making stuff colorful might exclude a market and we don't want that. Especially if the market is a trillion dollar enterprise-ridden bureaucratic hellhole, since those hellholes are where the easy money is.