Creating assets for specific games?

Sorry for my ignorance but are there many games out there which you can create and sell game assets for?

And have you had much success selling assets for specific games? And if so what were those games?

TF2 and Dota2 kinda supported that model, but you had to hope that Valve picked your asset to sell as an in game cosmetic, and they’d give the creator a cut of sales afterwards. I don’t know if it has changed much since it first started using that model.