Doesnt player progression make player position and differentiation irrelevant?

Im a fairly new player, so forgive my ignorance, I really do want to learn more about the subject

but the fact that you can build a player any way you want makes player selection pointless

and people that use the feature complain about the realness of this game

but if you take a slow irl player and make them fast, how is that realistic?

if you take a player that irl couldnt jump and give them 95 jumping, how is that realistic?

I see players retraining midfielders to be cbs or cfs, how is that realistic?

at this point, why have a ronaldo card and a ferdinand card

just call the cards player a, player b, player c etc

let the user train them according to the position they want and give them the equivalent name