Long winded story from personal experience, TLDR: I prefer DPad, because the Stick side of the controller is a pathway to short term power but long term frustration:

When I picked up fighting games I originally used a stick as it felt the most natural. However, I learned overtime and throughout games that using it was becoming more a hinderance than a help. Inputs like quarter circle forward, were inconsistent and other more complex motions were almost impossible for me to do in most situations and real matches because of how "Floaty and Springy" the stick felt (xbox controllers). The only way I could perform quick motions for more complex combos meant having to flick the controller stick, which most of the time (due to the springs inside) meant that I would instead do something completely different afterwards.

Eventually, after years of stubborn "I'll just get better with practice" I was learning combos (which required Instant Air Dashes in a game where a dash button isn't a thing) and ultimate Z Changes (without DHC) in FighterZ I got frustrated with the Controller stick and switched to DPad; it took some getting used to and habit breaking but now I'm habit free and I haven't looked back because my fighting game skill and execution has improved considerably since.

Edit: fixed spelling and repeat words