Finally, I found at least 1 really useful AI service.

The service

It's called CodeRabbit, the idea behind it is pretty simple, AI review code changes and give you recommendations how to fix it with explanation.

AI is working as pattern recognition, so, it's perfectly suitable for recognizing antipatterns in pull requests.

How it looks like

After PR created, GitHub action run and analyze changes. It's post summary like this:

The second comment contains recommendations:

Conclusion

This service already found few minor mistakes that I missed. Definitely worth trying.

Reviewing PRs is a very tedious task, AI can actually help with it.

Of course there are probably 3 useful comments out of 10, but it is very similar with human reviewers, e.g. they're either nitpicking the every line or blindly approve huge PR.

Treat such comments as possibly useful recommendation, not like obligation to fix everything.

Price

Currently, you can use it for free with basic functionality, and 12$/month for Pro version.
Probably, this promotion-like pricing will change in the future, but again, worth giving it a try.