Comment threads everywhere (including on commits and lines of code), these comment threads then having emoji reactions, and the inability to disable any of that (same for the pull request feature, which also leads to more comment threads) can get somewhat annoying when a group has decided to target you for arbitrary reasons, and such potential 'needing to see harassment' being deeply embedded in one's code workflow (i.e. in your own repository) can get tedious.
Not everything needs to be turned into an embedded discussion forum.