The only one that directly annoys me is not being able to have threaded comments at the PR level. https://github.com/github/roadmap/issues/552 You can do it with "quoting", which is fine if there are two of you but turns into a mess if there's more than that.

They've said that they're watching the discussions for feedback, so I hope they listen and implement that one.

Happy that they are being transparent (rather than letting the issues rot), annoyed that they appear to be prioritising marginally useful AI stuff for basic UX.