I write code exclusively in vim. Unless you want to pretend that ctags is a proprietary version of an LSP, I'm not using an LSP either. I work at a global tech company, and the codebase I work on powers the datacenter networks of most hyperscalers. So, very much a real project. And I'm not an outlier, probably half the engineers at my company are just raw dawgin it with either vim or emacs.