Correct me if I'm wrong but lefthook doesn't run its hooks exclusively on the staged changes IIRC. pre-commit, and prek by extension, have a process to stash the unstaged changes using git and running the code only on the staged files. Last I used it, lefthook ran on every file regardless of git status. This annoyed me because I'd have a few stray files that were not ready to be checked in or tracked that would trigger failures in lefthook. At the time this also made some hooks run slower since it would run on every single file but I think most linters have become significantly faster now.