Hear me out: prepare and teach your child about computers by stepping through generations of hardware.
No 21st century kid is going to want to use an 8 or 16 bit microcomputer from the 80s. But a kid running Windows 98 with only airgapped internet access, basically can't get in trouble and has access to decades of extremely dope software. They'll have the ability to learn and explore computing without it being a dumbed down experience trying to shuffle them into hell world.
A more modernized equivalent might be setting them up with a Raspberry Pi or LattePanda or the like running a basic Linux install that they can learn how to use.
Just slapping a kid down in front of a modern OS or god forbid something like an iPad is going to leave them entirely tech illiterate and primed to actively seek out the dopamine spiral of capitalist slop content like their classmates.
I don't really have a good solution for the culture gap they will have with their peers, but it sounds like you already have decided not to expose your child to the monoculture by ushering them away from AI slop and the various fascist influencers like Mr. Beast.