Why? 3 longterm managers since the takeover, all won leagues and cups, Pep winning the most while spending the most and having the best depth of quality. As long as the money is there, the club is successful. One Champions League final in 7 years - with the resources available - is hardly indicative of some indispensable messiah.
A more exciting, direct style of play that allows the likes of Foden and Grealish play their natural games and maximise their unique talents would reinvigorate the club.