by the acceptence of AI use within art
I have doubts about that acceptance. Coders will use it as a tool, yet will call non coders that use ai "vibe coders" as a slur and see them with contempt.
I am less sure about professional artists, but I am gonna assume that acceptance there is less than it is among coders. In a professional setting, it might be completely different than with an actual art setting. "art" can be a regular job for some people. Using ai to them might not be much different from a painter using a spray pistol, instead of a brush. They do not do the craft to express themselves, but to earn a living.
So it boils down to what the customer wants. And if the customer wants a wall painted white, that's not the same as a customer wanting a piece of art on the wall in their living room.
Playing video games is pure recreational activity. So acceptance for "ai art" is very subjective and will be highly influenced by non practical reasons. There is a vast pool of video games to chose that do not use ai, so why bother with the ai ones - they have nothing to offer as a plus. With the exception of some novelty experimental games. But exchanging graphics with ai graphics is no benefit. One cannot even argue that the game is cheaper this way. Not if there are more than enough free games to play.
For small devs I kinda accept it, as they can use it as an enabler to create a game at all - unless they just spam slop. Those "devs" exist too. But for more professional and paid games, I have little tolerance for ai.
So it kinda baffles me, that there are people willing to pay for ai assets. And in no small numbers if we have a look at those sale numbers you linked. If devs are on the struggling side of arts and buy assets, ok. Obviously they have a budget for their hobby. But why do they think it is a good idea to spend the money on ai assets? I dare say, if you use ai for your game, you should at least use it yourself and not pay others to operate an ai.