Good look at how it works, usage and abusage, here.
My thought (and comment) is that if Premier League clubs were to be restricted to a fixed number of professional players, as per baseball (where it’s known as a 40 man roster), part of the problem would disappear.
Player A is a Liverpool reserve they bought from Crystal Palace when he was 17 because they thought he might one day be good. Now he’s 19 and hasn’t played much. So they loan him to Burnley where he gets good game time. Then he comes back. Next year he goes to Watford. etc.
If Liverpool had to limit themselves to 40 professionals then Player A would try to find a club lower down the pyramid. He might catch on at Norwich, say, or may even go back to Crystal Palace. And whoever he replaces is forced to make a similar downwards adjustment.
Otherwise we’re faced with players being hoarded, signed at the first glimmer or promise then ferreted around or left to rot, depending on their situation.
I don’t know if 40 is too many – it feels like it is – but something like this would surely help end the current farce.