What's wrong with Minecraft? I'm not exactly a Microsoft fan, but am pretty impressed with how little control they have so far exerted over Java Edition, they even made modding easier recently by removing obfuscation. You can run your own server as much as you want with no fees, obligations or anything. And unless the kids know a server address, they can't easily join some third party server with weird stuff going on. Not that I ever heard of one of those, but I'm sure they must exist.

Roblox is a dystopian nightmare in comparison.

As others have said there's a big difference between the Minecraft "we" (the tech community growing up on Beta versions of Minecraft) know and the Minecraft of today.

The subsequent versions also developed the game mechanics a lot to turn it into something closer to an RPG than the early, bare-bones sandbox game with minimal, well-understood mechanics and the rest purely up to the players' creativity.

There's nowadays an abundance of Pay-to-Win servers with custom mechanics to enable that, and I'm sure a lot of unsavory people preying on children. The social media (YouTube/etc) community around it has exploded too in a way I don't recall it before (I used to be into Minecraft videos back in the ~2012 era, and what I see nowadays grosses me out in comparison).

Minecraft is infested with ads including massive in-game ads and advertisers are all over servers, popular online influencers, etc.

https://www.minecraft.net/en-us/article/lacoste-x-minecraft

https://minecraft.wiki/w/Universal_Studios_Event

https://pitchfork.com/thepitch/how-the-hell-do-you-throw-a-m...