Piccolo curbstomps.
U6 Saga Piccolo > 3rd form frost > Base Goku/Vegeta >>>>> SSJ3 Gotenks
TOP Piccolo >=< Ultimate Gohan
Ultimate Gohan = TOP SSB Goku = SSJ1 Kefla >> Base Kefla >> SSG Goku > Dyspo >>> Hit > post-Goku Black Arc SSB Goku > Goku Black > U6 SSB Goku > Frieza arc SSB Goku >>> BOG SSG Goku >>> SSJ Vegito
Heck Piccolo might even be above SSB Vegito based on how you scale.
Well Piccolo was much weaker than Gohan at the ToP.
Now it is debatable how much.
I recall Piccolo stating that when he was beating Gohan, Gohan wasn't even as strong as his past Mystic self, then we don't know how much stronger Piccolo was to that Gohan who was stated that weak.
The Gohan that managed to stall SSB Goku would have definitely decimated Piccolo.
There's concrete chance Piccolo is still stronger than Vegito so I made the thread appositely. xd