League on average have a strong economy that supports teams to bring in quality players, it is easier for coaches to bring in the players they want because of strong economic support. Manchester City have proven that their economic power is able to improve the quality of the team by bringing in classy players. Guardiola's effect was also very influential in Manchester City's success last season, he who has experience winning the UCL trophy with Barcelona was able to develop the players that Manchester City has to achieve historic success for the club. This season there will be more tough opponents in the UCL, Manchester City will have difficulty defending the UCL trophy if they are not consistent in maintaining the quality of their games.
Just having enough money is not enough but we need to know the proper use of money. Manchester City has not only achieved so much success in exchange for money, the main reason for Manchester City's success is their team manager Pep Guardiola. Pep Guardiola is a very skilled man, firstly he was appointed as the manager of the team and he was given the freedom to buy players at will which is why he has been able to make this team so successful. If we only consider money then PSG is a complete failure because they have invested a lot of money just to do well in Champions League but they have not invested so much money to do well in Champions League so far the main reason is that they have recruited good quality players but no good quality,l. Could not assign manager. PSG would have been favorites for the Champions League if they had hired quality players as well as quality managers from the start.
Now in this case I agree with you that money is not enough, they must also be able to utilize it well. And what Mamchester City do is they have both, firstly they have the money and secondly they know how to use it.
Other factors such as the coach will also have a huge impact on the game, not just the coach even the management will also be a factor where the club's success will be achieved. For example, if they want instant results, obviously it won't be easy and I can even say it's impossible, but what they do is trust Guardiola's process.