As for Josh, I think it's the end of the road for the Tartan Warrior, too much wear and tear already, but at least he had accomplished to be a unified champion at 140 lbs.
I do agree, he should hang up his gloves for good now as his unfinished business with Catterall has been settled already and it was clear that he was on the losing side and there is no excitement anymore for the fans of boxing to have a trilogy.
It's just the wear and tear on his body. Even in the weigh in or face-off, you can visibly see that somewhat Josh Taylor looks old. And he might have a hard time getting into the 140 lbs limit here, although he did make it in this fight, in the future as he gets old, his body needs those added weight.
So I do agree for those fans who are calling for him to quit. There's no sense of a 3rd fight when by now we clearly see the Jack Catterall should have won the first fight if not for the judges who gives favor for Josh Taylor. And then Taylor just avoiding him for years maybe because he knows that he can't beat Catterall, IMHO.