The way I see it the PL is at odds to achieving an ongoing conveyor belt of world class domestic talent. The number of foreign players increases every year, it simply will continue to do that. Last year only 33% was english. As every team is now awash with money it will potentially plummet.
The average spell of a manger in England right now is 1.2years. Youth players are in the hands of managers. But why would a manager risk playing a unproven 19yr old when the club has a transfer budget of £30mill and you can buy someone with more experience and more likely to get you results immediately which is what the owners (and fans and media) demand. A prime example is Gnabry at West Brom.
So clubs have more money than ever and managers have less time to succeed than ever before. ergo there will be less players coming through the ranks. Whilst english players make up the majority of teams in youth there too the % has decreased. Clubs look abroad to supplement their youth ranks as well. Just have to look at ourselves there.
Having a conveyor belt of world class talent is a numbers game and in England those numbers are being squeezed.
That is obviously only half the story as we have a massive problem in developing players into potential world class talents pre 18 across the whole country which is a problem for grassroots and clubs outside the PL where I'm pretty sure everything is still rather draconian compared to academies in Europe. That too is ultimately the fault of the FA and I honestly dont think a) they have the balls to get the PL to be far more domestic talent orientated and b) have the know how to actually transform grassroots coaching and development to the extent that it would yield massive results (like our olympic sports), mainly because like FIFA its full of old cronies.