With teams like City you can only lose as a coach, it's a different kind of pressure.
The football has changed dramatically over the last 10 years and working as a unit with controlled pressing in packs and variability in different systems are elementary these days. Pep showed what is possible, if the team consists of amazing players, but also working as a unit with clear tactical approach. Fairweather football from Real was outclassed and not able to compete.
Same happened in Germany. Dortmund with coach Klopp came around and showed everybody, that a hard working team with pressing approach, quick transitions and some great players is enough, to smash old school teams like Bayern with better individuals, but outdated tactical approach. It was a painful lesson to learn, that u can just compete, if everybody is fighting hard and doing defensive duties. The result of it was seen, when Heynckes won the treble with a hard working, but also brilliant technically team.
What I try to say is, that there r plenty of coaches, who r not able to adapt to these new circumstances and r going to be left behind. Heynckes for example was able to adjust and finished his career on a high. Ancelotti is another example of somebody able to adjust. Unfortunately, IMO, there r many others, who cannot adjust and Pellegrini is a prime example of that and seems unable to learn. Its also no coincidence, that Wenger, Mourinho, van Gaal & Co. look more and more clueless year by year. Their ego is prob too big to change and reinvent their approach, that made them so successful. Ranieri on the other side visited Klopp and Co. and was open to learn new things and again u can see, what is possible with a more modern approach with pressing and high intensity.