PSG was exactly the wrong move for him. You can see why wanted him, they had a bunch of stars who don't want to put in the required work that you need to truly achieve at the peak end of football, and they wanted to get past that. Poch's Spurs were just about the hardest working team in the Prem (and the dirtiest) and they figured he'd be the one to whip them into shape.
Except PSG didn't want to get past it. Not really. They make the right noises occasionally, usually when they get knocked out of the CL, but in truth, they prefer just having stars around, sitting in their Ligue 1 comfort zone, where stars can win you the league 9 times from 10. You don't continue with Neymar and bring in Messi if you want to be a technically tight and committed team, like Bayern showed last night. Which hung Pochettino out to dry. He ends up having to play star studded football, which is not his thing at all. He failed, and got burned.
Unfortunately, football moves fast. Not only is his reputation now tarnished, but there's lots of new managers on the way up too, so high pressing, hard working, tactically flexible managers are not so rare as they used to be.
I still think he'll get a shot at resurrecting his career, he's not in Allardyce limbo just yet. He could do well in Italy, and Simeone's time at Atletico seems to be drawing to a close, he'd be a good fit there. I don't see him at a big Prem club though, other than as a hail mary by Spurs or Chelsea.