I don't understand how this is a difference between stacked diffs and feature branches. Github allows you to use feature branches. I can see there might be some convenience with tooling
It's a fair question! There are a lot of perks to splitting up your change into multiple PRs rather than one feature branch. You can parallelize getting reviewed while writing more code. If CI fails, it fails on a more narrowly scoped change and is easier to debug. If something about one of your changes is unmergable, you may still be able to merge in half of your stack, rather than your change being all-or-nothing.
A lot of the benefits remind me of other dag-based workflows, like CI, data pipelines, or build systems. Does that make sense?
tl;dr the difference is a stack is merged partially as it's built out (that reduces merge conflicts, allows you to revert individual parts as found) and a feature branch is long-lived. Hope that helps :)
