Brehme, there two things that I am certain of when it comes to you: (1) your love for Mauro Icardi; and (2) your unyielding love of Mourinho.
in relation to the former, I often wonder if you are one of his pubic hairs. Regarding the latter, you simply can’t accept his decline.
Appreciating Icardi as an Inter player during (most of) his time here doesn't mean I "love him".
Mourinho 'declining' isn't a real thing. Coaches don't really decline or improve much, they just have bad fits. One bad decision and you're out.
Hector Cuper: Sacked by Inter, decided to sit on the money rather than get another top club job (he had 3-4 offers) and eventually went to save Mallorca during the last months of his Inter arrangement. Disappeared after all that.
Laurent Blanc: Was actually a decent coach. Sacked by PSG, sat on the money. Then waited for the France job that never came. Now he's been 5 years unemployed and no serious team will hire him. He ended up in Qatar, not doing a really good job either.
Frank de Boer: Never was a really good one, but enjoyed success with Ajax. Came to Inter late during pre-season, failed abysmally. Then decided to hop onto the first job that was offered and made a fool of himself every single time. He could have found something similar to Ajax and no one would say shit about him.
Unai Emery: Great for Sevilla, made the mistake of moving to the Arsenal graveyard and everyone thought of him as a joke. Then moved to Villarreal and proved everyone wrong. But it's still Villarreal, he cannot do much more than that. As an asterisk, he was robbed by UEFA in the 2016-17 season against Barcelona. 2017-18 is on him, but that's vs Real Madrid and generally PSG didn't have good relations with UEFA at the time.
Roberto Mancini: From architect of Moratti's successful Inter in the 2000s, to the builder of Manchester City... to someone who moved around Turkey and Russia and got the job that nobody wanted with the Italian federation. He'll definitely be sought after when the World Cup is over (whatever the result is and even better if they are great). Something that no one could have said after his Zenit tenure, right?
The only rare exceptions that managed to get top jobs after making "questionable" choices are Carlo Ancelotti and Rafa Benitez. And that's because Real Madrid's hiring policy is weird and political. Mourinho "failed" only at Manchester United, yet the results (ie trophies) say that he's been their most successful coach since Alex Ferguson. Going there was a mistake and he topped it by moving to Tottenham. Roma is just the result of those bad decisions and on him not wanting to go to Juventus, where he could have been a CL contender overnight. Do you doubt that he could have managed a great CL campaign with the gobbo squad?
Coaches don't "decline". If anything, they're rather stagnant between their mid-40s to their mid-60s and their 50s are considered to be their prime. The problem with coaching nowadays is that players have significantly more power than them. Mourinho just made too many bad choices and moved to toxic places with no real influence on changing the situation. At Inter, he'd be thriving.
If Guardiola moved to Tottenham and Roma by choice, you'd also be saying that he's in decline. Because he'd not do well.