I don't even like the guy, but the way you try dismiss the meaning of everything bar his work for Chelsea, where he still won the CL, is ridiculous.
He didn't just do well at Mainz, he performed miracles and he's a big reason for why they now have a fairly safe spot in the first division, instead of being a random team in the second.
At Dortmund his first season was a low key miracle as well, considering how things had ended under Klopp and the following year he did great in the CL, until the bus attack, and eventually won the cup.
At PSG he had a season north of 90 points and got them to the CL final.
And you summarize that as "failed to translate that to consistent top level management", what the heck?
I mean we all know that he has a toxic personality and that talking himself out of his job seems inevitable, but before that happens he clearly does good coaching work - unfortunately.