I know my take is controversial since ManUtd is an English team withh "playing youth players" as part of its core values, but I don't think it is wise to play our youth anymore, considering most of our youth products in recent years got poor attitudes/work ethics (Morrison, Lingard, Rashford, Greenwood, Pogba, Januzaj, James Wilson, Brandan Williams, Chong, Pereira, etc. even McTominay isn't that good indeed since he loves jogging back when we got countered). Even Elanga, who looked fresh and hardworking when he first played for us, got assimilated to the rest pretty quickly.
Modern English players (and French to a certain extent) are mostly snowflake and arrogant and love to treat themselves as KOLs instead of football players, we should try more players from eastern europe, Germany, Spain, Scandinavia, uruguay or Africa instead since most "warriors" type of players come from those regions. Even Welsh/Scottish players are better than English players somewhat.
to my best memories, many of our youth players sent out on loans to other clubs got criticized for their poor work ethics/attitude. I think there is something wrong deep in the culture of our club which has infected our youth academies too.