It still matter big time. Unless you don't understand manga trope/writing style.And Jiren got a backstory power up to even contend with MUI, so I don't see your point.
You don't have to like either, but once Goku saw Jiren try to hurt his friends he overpowered Jiren and had him at his mercy till his body gave up on him, Jiren would have been eliminated by Goku had this not happened. Does are the facts and i only debate facts.
It doesn't matter if it's MC power up or not MUI Goku is > FP Jiren.
Thinking it like temporary adrenalin pumping where you can pull something that before this it is impossible to performed. And nah Jiren's backstory moment can't be put in the same bracket with clear Manga trope.