Because as soon as the indie audience catches wind that a game uses AI for any code, artwork, or writing, there goes the "indie" cred. It's not cool anymore. Worst case, some ludds launch a vocal public crusade against you.

Rest assured, there is plenty of AI being used, but the game devs know better than to talk about it.

Fair point. But whether a game is indie or not isn’t really my main concern here. What I’m wondering is this: you probably know how much money simple games like Doodle Jump have made. It seems entirely feasible for a somewhat experienced developer to whip up a shameless clone—with a fresh coat of paint—in just a few days. Sure, it wouldn’t make a fortune, but it should still earn some money—enough to be worth the effort.

So why haven’t we seen a flood of these kinds of games on the App Store?

We have, look at Playstation store, App store, in the new games section. None of them are successful so it doesn't break your main feed. Someone can estimate no of game coming out with AI in them, but I am not that guy, I can give you a percentage and its like 70%.

Thats some bullshit, if your game is good and uses AI, users seem to not care about, for eg Arc Raiders.

But vast majority of games are shit and even more the ones where they use AI, and there is already enough slop on the market with AI, that users know they need to stay away from those games.