In "What you get with Atuin" the first(!) point is "Sync your shell history to all of your machines, wherever they are". That obviously cannot work with a local SQLite. Without syncing, this is a better ctrl+r, which I won't disagree is nice, but not the real point of this software. If the page says this is "trusted" by pretty much all major software companies, I would assume this includes syncing, which is the main feature.

Also, even the possibility that the software would send this to the outside would make this impossible to use at my company, and I don't think we are overly strict in that sense here.