To be fair, if you have 10 commits that all change the same file: squash with respect to your first commit, _then_ rebase. If you have lots of commits, always first squash-rebase to your own first commit, and only rebase to current main once that's done.

Rebase is being annoying here mostly because it's doing exactly what you want it to do: warn you about merge conflicts for every commit in the chain that might have any.