The point is when he did produce he got the chance. Sets up the winning goal after a less than inspiring effort from everyone else vs Palace and doesn't get a start. Comes on and tears City apart and presumably was dropped for Spurs injury or not. I don't know for sure but I'd bet he's started less than 7 games for Everton so acting like 7 starts in a half a season isn't more beneficial than what we've given him isn't true either.
My point with Spurs is they have the model we can closest follow. If Lookman turns out good it may hurt our reputation to have been unable to maximize that. Spurs have taken talents like Alli, Eriksen and Kane, none of which had played at the level they're at before Spurs, and turned them into top class players. Hopefully that is what we aim to do with players like Richarlison and Pickford but never giving a young, promising player a real shot isn't good for doing that.