If you want to encourage grass roots learning interest millions of gamers with 8gb cards is a better starting point. Even if only a small percentage go for it that's still million of people.
Meanwhile the number of people that has the luxury of shelling out for a 4090 straight away for AI specifically is pretty small.
It's a bit like raspberry pis helped the tinkering world even though they're realistically slow AF. (and now unobtainable sigh)