In the early 2000s you always saw young players develop at a team. It wasn’t just youth academy, it was guys like Ronaldo for example who developed at man united. Barcelona was full of youth academy guys. Arsenal used to build up young players. Now teams never build guys up they just buy them.
If you’re going to claim this, you should come up with some definitions and some numbers. What teams are we talking about, and how many youth players are they playing now, compared to earlier?