At young ages, I say give them an old-school Nintendo, or N64 etc. Little/no advertising, monetization of your kid's attention, whatever. If they're not on the web or at school yet, they won't even know they're missing out on more modern systems.

Or some similar setup where there's no online, no monthly charge, no pay-to-win, and instead the child gets to play a carefully crafted game, hopefully an awesome one.

I also think (offline) minecraft is great at that age.