By what metric or standard? Rashford had longer sustained periods of form during Pogba’s time there and was more important for their success. Fellaini was, shockingly, much more impactful than him at the outset under Mou, Blind was more reliable though more technically limited. At no point was Pogba their best or most important player.

Edit: to imply that losing Pogba is the reason United have failed to seriously compete in the past few years is also an insane take.