In my opinion there are so many possibilities being missed when developing players
Some examples: Playing a youth player (16-18) in his first senior game should impact his mental skills. Determination going up after getting a few minutes off the bench at the end of a league game/going up after a first start or down if the youth player is played in a match that is too high profile and he ends with a 5.90>, questioning his ability to play at the level, missing a chance (striker) or getting beaten to a header (Cb) or taken on multiple times (FB). This makes it so much more dynamic when choosing the right moment for the player, and protecting him from these situations. It makes it so much more immersive to have this impact. Also, telling that individual "well done" in the dressing room, or at least acknowledging the debut in the conversations afterwards. There MUST be more ways to work with these players. Confidence impacting quality should be extremely dynamic between 16-19. For instance. If my 17 year old youth player is scoring 25 goals in u18, surely his finishing would go up with confidence significantly in the early stages, (for example, 12->16 because he is high on confidence) and then you play him in the right moment in the first team and it sticks, or play him in the wrong game where he gets bullied and you find it right back down at 13. This makes choosing the right loan spell important and other features that can just connect the user with the development of young players and engaging in these kinds of choices.
When it comes to players 20-24, why is it near impossible to mould them into a player that fits the system, eg. making crossing a priority for your young full back and it actually changing his stat, or getting feedback in the early stages from a coach that it looks like this player is never going to improve in that area and its worth thinking about a different role, or moving the player on. There must be SOMETHING that can be done to make this game more in tune with development. If I signed a pressing forward who had lower finishing and wanted him to improve on it, it should either improve, or the coach tells me he just isn't a natural finisher, then at least I know what I am working with. Right now it seems like you can waste years on a player with no feedback other than the player not liking the training schedule. The coaches need to be giving better and more important feedback. Even set piece takers, its genuinely impossible to make a player, (even if they have high technique etc) a better corner or free kick taker, when in reality a player can improve these things if it is part of their training.
Finally, I would LOVE the ability to actually give players stat boosts because of my style of management. Example - Pep improves every players passing, touch and decision making because of the coach he is, so when signing a player with some potential, Pep's style and philosophy would give that player a boost in those stats. Having a style of a manager and being able to chose what is important to you would be a hugely important and engaging feature. Signing a player with 18 passing, and when he arrives it is only 16 because he was playing under a manager who emphasised passing, whereas the user emphasises (for example) fitness, work rate, crossing and these are all reflected after the player has spend some months at the club (and these stats get a boost) and in addition if you had (for example) Mason Mount (20 work rate) and your philosophy was centred around work rate and pressing, then Mount is more likely to regularly turn in effective performances because he fits the managers style. This is a more immersive way to recruit players that fit your systems, develop a system and philosophy and be able to change it over time (Pre-season meetings: I want us to be ruthless from set pieces this season [boost: corners, free kicks, heading, marking]) and gives huge flexibility and dynamism to signing players and having a plan. Adversely, going into a club with players that don't fit your system would make it much harder in the earlier stages.
If anyone thinks anything of these suggestions please let me know. But I'm getting exhausted by the lack of impact I can have in this game and it feels like going through the motions, signing the best players and trying to win games and that's all. I can get that from mobile games. I hope to see some changes in the near future.