United has been irrelevant in the last 10 years both in Europe and the PL. I have no idea what you mean by cheating, but let me tell you one thing, when outsiders think about PL, we mostly think about City, Liverpool or Chelsea nowadays as they are considered credible forces to have a chance to win the CL.. Also, do not mix Liverpool with United, Liverpool played 3 CL finals in the last 5 years though winning PL only once in that period helping them maintain their reputation unlike United..
If you think that the team that is breaking multiple PL records winning PL 4 out of 5 times last 5 years at PL's peak, playing great entertaining football will be a footnote in the history, I wanna know about your definition of footnote.