I don't agree with that. I can't think of many obvious talents from 1st/2nd round that didn't come on (maybe that Lamb guy from 2014 but he was speculative). We've had a bunch retire due to unfortunate circumstances (eg venables) and some taken with low-ish picks that didn't have the talent (Partington, Mutimer). Can you give any examples of players with talent that didn't develop and were washed out?We definitely have developmental issues.
The development pathways that deliver "draftable kids" are not so erratic as to deliver the woeful strike rate we have had since 2011 without some measure of fault laying at WC door.
EDIT: another thing to reflect on is how some players careers really flourished once Simmo came in. JK became one of the best in the league, Gov as well, Yeo became a midfielder. Sure, some of that may have been them hitting the right age to break out, but if the development was bad I would expect many would have regressed.