I'm not trying to answer for IGSpur but I think his point is a simple one: the players that he named were all very good at youth level and the difference between (for example) Wan Bissaka and KWP is that the former was given the opportunity to play and the latter wasn't. Very simply, the more players play then, generally speaking, the more likely they are to reach their potential. Ours are given relatively few opportunities to play and therefore their development is stunted.
But Winks followed exactly the same path. Not making his PL debut till 21. But he took his chance when presented it. KWP had a glorious opportunity but has not impressed most likely because he simply isn’t good enough. Not a single player we’ve let go from the youth academy has gone on to be great somewhere else. Just don’t know why people can’t accept that the majority of our academy just aren’t good enough.