Physical strength,endurance and stamina matters.In professional fighting you need body mass and hence in why we have weight classes.
The post i quoted was talking about "muscles" but i still assumed theybwere talking about strength and actually agreed that it is a factor so we are not in disagreement (although it wasn't about stamina). My post was also specifically about this particular fight where endurance/stamina wasn't that much of a factor (although it didn't hurt he seemed physically superior in strength and endurance). But even without these advantages, if he had slightly less muscle while being in the same weight class than his opponent he still would have won becquse on a technical, strategic, psychological level and just overall fighting IQ, he just seemed superior.
But yeah, i don't understand why you quoted me when I pretty much said it generally matters