OneUI... TouchWiz is a very heavy skin compared to oneui.Ive used both too(from s2-s8) and used a grand prime for a while.TouchWiz never felt the same as snappy as oneui.
What I like about samsung is they pack as much as features they can even we dont actually use them.But when we need them those features are golden.For a example do you know theres a baby crying detector and a doorbell detector baked into even oneui😅.
Also OneUI is very clean and polished and designed to help with one hand operation.
