This piece suggests (accurately IMO) the opposite, current u23s setup is holding players back for too long.
https://royalbluemersey.sbnation.com/2020/7/23/21335531/are-everton-misusing-the-under-23s-team-david-unsworth-youngsters-broadhead-baningime-youth
Think we need to be a lot better about getting more of our young talent the opportunities to step up. Otherwise it's too small a player pipeline to rely just on the few who, largely through lucky opportunity, can breakthrough directly from our youth games. Branthwaite is a perfect example; if not for already having a shortage in the position and forced by injuries, it might have been years before we saw him in a "competitive" fixture.
We've had 4 loan moves across our current u23 squad, 2 of those for players now aged 22. Set more of them the challenge, younger. Might take them a couple of loans as well.
Definitely want to see Simms loaned out next year, along with a handful of others (if keeping them). Some of the u18s could/should be looked at soon as well (Onyango in particular). Although getting more of the u23s out quicker would naturally push up u18 players to fill the void.