I think the benefits are quite obvious.
That's 3-4 players who you don't need to pay a transfer fee for, leaving more money to strengthen the remining places.
academy players are almost always on a lower wage.
There's a chance that the academy players will kick on and really increase in value, giving another income stream from selling them on.
It's definitely a good approach to take for a club of our size.
Bringing through youngsters is hard though - there's a reason Warnock didn't want to bother with it. They are inconsistent, make errors, and you never know how much they're going to develop. From a manager's point of view there's a good chance they'll be sacked before you ever see the benefit of persisting with them. However from the club's point of view its definitely preferable to having a load of ageing players on large wages that you can't get rid of.
Most other clubs in the division are doing it to an extent - maybe 2-3 debuts per season, with 1 or 2 in time becoming embedded in the first team.
having 3-4 of the team from the academy is ambitious and would put us in line with some of the better clubs in that respect.