A "success" is a bit of an understatement.
Since Klopp joined Liverpool he has won their first title in 30 years, won a CL, made a CL Final, made a UEFA Cup Final and collected a points total that would have seen them win the league more often than not, they have been pretty heavily invested in other things and quite preoccupied TBH. He has validated the decisions he has made.
City and Chelsea have had the depth and investment to be able to chuck that depth at a league season, Europe and Cups, they have had squads that are in reality football cheat codes.