Most of the language servers can run with Vim, Neovim, Helix, Kakoune, or Emacs as you noted. You could run VS Codium if you’re the “Tech Conservative”, but ultimately if you’re going all the way to “Tech Paranoid”, you won’t touch VS Code or Codium knowing Microsoft is steering the ship with another EEE plot in mind. It’s all a part of that package with Microsoft™ GitHub® + Codespaces® + Copilot® trying to vendor lock-in the developer experience into the platform.

It's "open source" as a technical matter, but the fact is that plenty of common extensions are still strictly controlled by Microsoft (like say, Live Share) and can't be used with vscodium due to licensing. It's a pretty useless editor without extensions, and the marketplace isn't exactly "open", either.