It's an extremely good question.What does success look like in the modern game?
For an owner it will be turning a profit.
.For fans like us surely it means glory and having pride in your team - you know having a go in games , winning matches , scoring goals , cup runs and whisper it an occasional trophy and qualifying for Europe on a consistent basis
Given the money spent by the top 6 it's obviously not easy . It requires good recruitment , judicious spending , good management and a lot of luck.