It's "sort of" a dark forest problem because admitting you're using AI is socially risky. Indeed, this entire thread is built on the idea that Epic's lazy use of AI has been bested by the savvy & righteous programmers at Valve[1].

So people who think AI is actually a really useful tool and that using it to make your project better will imagine that everyone who makes things better today uses AI at least a little, and assumes they don't talk about it because they don't want to get yelled at. Meanwhile, if you think AI does bad work (or is often used badly) you can ascribe bad software to bad uses of the tool. We can never know for sure because people don't talk about it.

[1] I happen to agree with this dichotomy but that belief precedes AI