I did actually try CCLS first, but this was several years ago so it's possible that it may work better (something about our codebase was causing it to crash) - I should try it again.

Lacking LSP didn't stop me from using spacemacs, though. Oh, no. emacs has an auto-complete mode that just chooses from a pool of symbols already present in open files and that turns out to be Good Enough for me to prefer editing code there vs Visual Studio, IntelliSense be damned.

My employer furnished me with a beefy enough workstation that I can have Visual Studio open (to semantic search the whole codebase for stuff I don't already known where to find and to build/run/debug) alongside emacs (for editing and general code browsing when I know where definitions live).