UIs can be nicer though for rewriting / making finer-grained splits than the hunks that -p decides on, definitely agreed there. I have broken out a UI just to simplify staging some gnarly commits. GUIs are also often nicer for understanding and resolving nasty three-way merge conflicts.
distributed VCS is neat and all, but the vast, vast majority of cases have a canonical source-of-truth repo somewhere, and the rest are effectively just private mirrors. for those cases, distributed is mostly a significant source of complexity rather than capability. though it is significant to have an "escape hatch" when you need it.
I repeatedly run into this using the interactive features.
but for me a bigger reason to prefer a git UI is that I can actually see the graph. I can do things like drag branches between commit nodes. I find this so much easier and safer than the cli