He's been slowly losing it since Real. At Madrid he had his first experience at serious adversity. A number of things have slowly contributed in creating a put bluntly bang average manager in the present day.
He never before Real had a squad and fanbase with the vast majority not fully behind him, he never before had a manager have such the beating of him as Pep did. Although he created a team that toppled that Barca side to a title which was a great achievement he never went all in on trusting a squad and fanbase again.
He returned to us and while his tactical astuteness was still evident (especially in big games) something was missing from before, the title was great but i feel he went all in on achieving it with no thought for the bigger picture, and it showed. I think 15/16 was a killer for him, even not as good in the 00's he still had that aura about him, that half season destroyed that, the man who's teams always challenge for titles is now fighting the drop and it happened at the club he made his name at, that made him even more paranoid and doubting himself.
At United at the start i felt ironically he reminded me a bit like Rafa at Liverpool, capable of the odd masterclass and cup runs but ultimately didn't have the consistency to challenge for titles, Conte outperforming him at his ex club hurt him badly, you could tell by his tone everytime he spoke about us. I think since it went wrong with United he's suffered even more psychological body blows with the knowledge he's blown it at the world's two biggest clubs and a club he spent the best part of a decade describing as his club, and then with the Chelsea job vacant and him available we choose Lampard, that must have ruined him probably even more so than Conte's title win here.
At Spurs i cannot identify a single characteristic that made him great. His big game record is hopeless, he isn't training the defense well, he isn't making his home ground a fortress (he was still doing that as recently as United), he doesn't appear to have a clue how to turn the tide of a game, he doesn't prepare his teams properly all the things you could have banked on as a minimum at Chelsea 1.0 and Inter.
I do feel sad how much he's fallen when i truly think about it, if someone told me in 2005 that 14 years later i'd wow to cancel my club membership if he returned i would have laughed at them. I think he doesn't enjoy football anymore which may have stemmed from losing his dominant aura, when he's on a break from the pressure's he does seem quite a happy person so maybe for the sake of his mental health he should consider if it's really worth it anymore because a job he use to love is making him miserable and he's putting more and more dents in his legacy the longer he keeps trying (exactly like Wenger apart from he's doing it with multiple clubs instead of just the one).