the value of the game would decrease to 0 as there is no effort in the game
Artists don't like AI at all mainly due to stealing their artwork
Do not use falsehoods and untrue generalizations to argue against ai. It weakens your point.
The "value" of a game decreases, yes. Using ai is not a selling point. You cannot advertise it as a highlight to be proud of and some people actively avoid ai.
But the value does not drop because there is no effort in the game. That is not true. Create a game with effort 100. Now add a few gen ai assets. Adding those extra assets took effort and you now have a game with more effort put in than before. But the "value" still decreased in the eyes of some customers, but not 0 overall. It it had value "47" before, it now has value of 47 + extra value those assets give - negative reaction against ai. That can be 0 for individuals, since they see ai as a deal break, but it will not be 0 for the average customer.
There are artists that do like ai and are using it. The premise is wrong already. But you continue to claim it is mainly due to stealing their artwork. This is one aspect, but the main reason is competition. That the ai might have been trained by their work only adds insult to injury. The competition would still be there if those ai were 100% trained by consented art and those artists would not suddenly accept such ai.