It won't.
Making games isn't actually that easy? I've been doing it for 25 years, and making a game that's good that people enjoy requires, in no small part, that you yourself enjoy playing games, and that you understand what fun is.
It's not just the designers that make games fun, either, even if they're responsible for a lot of the mechanics. Every breakdown of job responsibilities I've ever seen (which we use come review time) has something in it about how you understand game mechanics and your ability to make contributions in that regard, and that's regardless of whether you're in design or art or programming. As a programmer, I'm not tasked specifically with making the game mechanics--I'm there to make a platform for designers to execute their vision--but I have made changes independently that have shipped effectively untouched in the final game.
So all that to say, if you use AI to write your games and you're not a solo designer, your games will probably be worse. The bigger the game gets, the more you'll feel the lack of scrutiny from individual contributors. Any of the small, interesting, fun details you've played in a game up until now was almost certainly put there by a real human that wanted that to be in a game themselves.
There's a possibility that AI will make my job easier or make me a bit faster, but I'm not losing my job to AI (though a greedy CEO may blame it on AI). There are ALREADY a zillion games out there. The barrier to making games is low. If all you want to crank out is slop, bad news: humans have been doing that for decades now. Slop by an AI agent isn't actually going to do any better.