Fury is a beast. Imagine if the dude had more muscle on him instead of the giant dad-bod.
He lost a lot of weight for Fury Vs Wilder #1
Felt weaker, didn't win on points, fired his young coach.
Went back to his regular routine, gained the weight back, smashed Wilder on #2.
I think we shouldn't judge just on look when it comes to strength and power. Fury is totally ripped under that flab, that is probably needed to feed him that extra energy and punch weight.