Just to say: This is avoidable. Ofc one can not give Windows to a child anymore, but there is Linux. For games on Android, of course one can't install games from the Play Store anymore, but there is F-Droid. And for regular PC games, there is still a big selection that works without or with very little micro transactions. And besides, the kids system should not be capable to make any purchases no matter where they click.

But I can completely relate that it is infuriating and that it takes a lot of filtering through the mainstream shit to manage this well.

Proprietary/popular games on Linux come with the same monetization strategy on every platform. You want to play Fortnite, you get the Fortnite ads/loot boxes/nudges even on Linux (plus you'll get banned by anti-cheat quick).

Linux is not the recommended choice for the game selection, it's so that the OS is not already a hostile place with ads and spammy news. The games themselves have still to be filtered, as I wrote.

That's what I use myself, but I can't really recommend it to family overseas... And even that is not safe, this will probably be the last Ubuntu release I can use before the "Ubuntu Pro", Snaps, and other integrations become unbearable.

In the same manner one can avoid many bad aspects of modern cars if they are an experienced mechanic and can build their own, but that's not a reasonable burden for an average person.