I greatly appreciate Vim’s stability. But it’s also not only Bram that can develop it, especially on maintenance patches (as distinct from new features). I can’t think of any particular times anything regressed in Vim, except that I have a feeling there was one. A few times over the years I’ve found bugs, and each time, I’ve either submitted a patch which has been rapidly accepted, or reported the bug and it’s been fixed rapidly by Bram or someone else.