I'm not sure this is entirely fair. We saw in the 19/20 season Juventus began to manage his minutes, I seem to remember him being left out completely 5 or 6 times in games they were expected to win. They couldn't do that last season as he missed a few games with COVID early on and then they did leave him out once or twice and IIRC they didn't win any of those games, as such they'd had a poor start to the season and were playing catch-up so they essentially played him all the time and in fairness he ended up being the top goalscorer in the league so you can see why they did that.
So I don't think that he is necessarily demanding to play every minute of every game, it's as much as a case as we need him to as we have no other options. We've got Cavani who seems to only play if he can be arsed, Greenwood is no longer an option for obvious reasons and Martial decided that was the window to demand a move. Couple those issues with Rashford being as out of form as he's ever been in his life and we basically have only Ronaldo available up top which is ridiculous as I certainly don't think anyone was expecting to see him having to play 4 games in 11 days when we signed him.
I also think while it's clear he is nowhere near the player he was, he's being asked to play a different way in this team to what he's used to. He's used to having players around him, throughout his career he's come in off the wing where he can pull away and find space, generally even now that's where he looks most dangerous. We're asking him to constantly occupy the oppositions centre backs with only Elanga ever willing to run beyond him. You see in the moments we do get players close to him that he comes alive but he's so easy to mark out of the game while we keep playing him through the middle on his own, but as I said before, nobody else seems to want to play up front for us.