Spending money has never been a guarantee for success for any team at all because they may still spend all the money and not be able to get these players on the right strategy that will bring about the results they aimed to get buying these players, such was with PSG some seasons ago when they bought Messi and Neymar, meanwhile mbappe was still in the squad aswell and yet all they got was their league title.

Away from team quality and depth, sometimes tactics and strategy of the coach aswell as the psychology the team provides the players has got a whole lot to do with the performance of the team, so I don't think it's totally going to be a function of just getting the good players and the team will miraculously start been at the top of every league and winning their games aswell. In the bundesliga, last season neither of Dortmund or Leverkusen spent so much on buying players but they were both very productive that they were able to get some achievements in certain ways.

Dortmund has even been known to be a team who has their way around training young talents to becoming to notch players and selling them off which at the end of the day they make more money from them. So they are a very good example as to what the performance of a team can be with or without buying players, it's even much better to nature young talents than trying to buying players just like Leverkusen did nurtured these players and they are now of good assets to the team.