Yeah you can improve with age, sometimes by alot, but mainly with offensive players IMO (more confidence/mentality thing with them, being in right place in right time to grow), or defenders who are governed by their mental fortitude and experience in handling sitautions.
But with DMs&defensive CMs even if you can find different roles or grow with experience, your overall abilities rarely change much. If you are a water carrier type of worker like Sturaro, you arent likely to suddenly add different more varied qualities to your game to do completely something else. Marchisio defenitely improved, but its also because his core abilities was allways well rounded, technically, offensively, in passing, decent tackling. Its just that he stopped being lost in being jack of all trades that was put anywhere they pleased that was detrimental to his growth, to now truly finding his role with experience. But the abilities that make him strong in this holding role isnt new one, tactical knowledge and positioning is prolly something you gain with experience. But how he controls plays, passes, reads things, tackles or high technical elvel is qualities that been his partly for most of his career.
His flaw rarely been lack of ability in the past, just lack of consistency to find where would fit. For example he was never a 4-4-2 player but thats where he played mostly prior to Conte (briefly 3 man one with Ferrara). He was too soft for hard task of 2 pair CM role, so they pushed him wide or box to box more upfront. But with Conte he find exactly the 3 man midfield to fully more express himself with less burden or less need to be pushed wide/too high up. To coming full circle as holding mid. A nice trajectory of mediocre/inconsistent CM/winger in 4-4-2's to fantastic box to box CM in 4-3-3/3-5-2 to now IMO world class holding mid. He has allways been a player thats adapted to where he is needed too much, but thankfully being pushed out by Pogba from starting eleven made them realize he is by far the best fit to play in holding mid after Pirlo. A blessing for sure.
I got sidetracked, but point I was making is even if players can allways improve, I just dont see someone like Sturaro improving to such a degree thats necessary like those examples you gave. His player type is fairly straight forward limited hardworker ones. I dont see that extra abilities in his arsenal to grow to another type of player (tactical awareness defenitely, but the other qualities you mentionned, you should have the affinity for them already at 22-23 to truly express yourself at them). And his current role he is aggressive and his all, but generally thats not enough in todays game where midfielders have to be so complete.