I don't see a problem with Goku losing. He came into this tournament wanting a good fight ("I can't get no satisfaction!"😉. Jiren gave him a good fight and then some. Possibly the best fight he has ever had in his entire career, pushing him further than any opponent has ever had. As far as Goku is concerned, his goal from the outset of this arc is satisfied. Not to mention that U7 wins the tournament anyway, so no biggie. A least a Frieza win gives some pretense that teamwork actually mattered in this arc when we know it didn't.
Horrible storytelling is having the protagonist get taken out by some random nobody after spending hundreds of chapters building your protagonist up for greatness. Horrible storytelling is Hajime no Ippo as of late.