No offense @Lord Blackadder but I don't know why people even bother talking about teams like Barca, Madrid, etc etc.
It's not real football.
It's make believe FIFA 18 video game stuff.
It's literally fantasy football.
They are both always good, they win all the time, they always have the best players.
Any problem they have they throw money at.
That's not real football.
Of Real Madrid, Johnathan Wilson says "[Real Madrid] are a club that have habitually placed resources over theory and [have adopted a] magpie approach, gathering up the brightest available stars and shaping what they could from them..."
It's true that Real and Barca rely more on their financial clout than on tactical genius to win matches (Both Manchester clubs, PSG, Bayern Munich, and Monaco have also functioned this way at times) but outside of that financial stratosphere you do see managers who are advocates of a pressing game - Pochettino, Klopp, Bielsa, even Conte. Of these, Pochettino and Conte play a more conservative press with more defensive solidity. But even they demand that wide defenders also function as attackers.
To be fair to Pep, he has a very clear philosophy and, despite having unlimited resources, he builds attractive teams who are not just a collection of talent, but a collection of talent bent towards creating styles of football impossible to replicate with anything less than a totally committed group of world-class players.
Mourinho and Simeone are-results oriented managers who know how to build a defense that can break an opponent's attacks like glass (heck, you could even say the same about Tony Pulis and Big Sam) - but they are also horribly dull to watch and also often rely on tactical fouls to unsettle their opponents. Defensively solid they might be, but I don't want any of those manager near any club I support.
Pressing is risky, hard to implement successfully, and always carries the chance of the kinds of short term collapses that see Liverpool concede 2-3 goals in a few minutes every few matches. But it also allows them to score 2-3 goals in as short a space, and is exciting to watch. It's never going to catch on below the upper echelons of the elite level, but I still enjoy it.