Actually in this case, it's not so much that the Switch version looks particularly impressive, it's more that the PS4 version specifically is disappointing. I tried the demo on my PS4 Pro, and it doesn't look good. It honestly looks like a Switch game on PS4 Pro. Which is pretty bizarre considering it can clearly do better. Particularly where resolution is concerned.
In contrast, Dragon Ball FighterZ looks phenomenal on a PS4 Pro. And is a clear step up from the Switch version (though the Switch version does looks great in its own right).