No doubt he was a very good manager back in the day but really his heyday was 15 years+ ago.
Then again, you do need the right club and the right timing. We can say he hasn't won a league title since Chelsea in 2015, but I think any manager would struggle to win the league with the rags team he had, spurs and Roma and I'm not sure how many managers could transform them into a league winning side either.
If he goes to PSG, Bayern etc after winning the league with Chelsea 9 years ago, he wins the league with them in all likelihood and is still considered successful in current times. You could say taking the rags job was a big set back.
I still think he's probably a good manager, he won trophies with the rags and Roma, not to mention he got sacked before a final with spurs. Considering none of these teams at the time were realistically league contenders, he won them the only trophies they're pretty much capable of winning.
So it's fair to say he still does know how to win things in relative to the realistic position the clubs were in. So it might be a bit unfair to say he's finished.
Problem he has now is I don't know think clubs like PSG,Bayern etc would employ him now, even though he would probably still do a good job there.