Squash loses the commit history - all you end up with is merge merge merge

It's harder to debug as well (this 3000line commit has a change causing the bug... best of luck finding it AND why it was changed that way in the first place.

I, myself, prefer that people tidy up their branches such that their commits are clear on intent, and then rebase into main, with a merge commit at the tip (meaning that you can see the commits AND where the PR began/ended.

git bisect is a tonne easier when you have that