It's alway pretty fascinating to me that people can actually be productive without an IDE. I've tried several times Vim and I just don't get it how you can live without certain functionalities, I'm sure that with enough tinkering you can get pretty close but, for example, search seems to always be kind of a pain in the ass for the complex queries with regex through many files and stuff like that, specially the presen…
Regarding your specific examples, both vim and emacs have file histories and if your files are under version control it's easy to get diffs.
Searches are super powerful in both vim and emacs, and it's easy to search across multiple files as well using various scripts/plugins.
The main downside to using editors like vim and emacs is that you have to be a pretty advanced user of them and spend a lot of time configuring them to really feel their power. If you've just dipped your toes in they're not going to look very impressive and you'll likely be disappointed.. but invest the time and they're very hard if not impossible to beat.