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
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 :)