Comment by teeray

It’s the “well-curated” part. Many folks treat commits like video game save points, and find providing any kind of message burdensome (e.g. “fix bug”, “do work”). This alone is fine, but then they can’t be bothered to go back and clean it up with `git rebase -i`, so you end up with a mountain of trash in your git log if you don’t turn on mandatory squash and merge. For these folks, the PR becomes the commit. Stacked PRs is revolutionary because it’s as though these developers can finally have multiple commits which comprise a change.