Ronaldo is the best player in united and they will do anything to reserve him in the club in the January transfer market. His presence alone put fear in the mind of defenders. Ronaldo is aging but he's still dangerous as of when he was young. So much respect on his name and Erik ten hag will be giving Ronaldo playing time now that he knows that he would give him positive results. United might likely end in the top four this season because they're trying to win games.
Ronaldo is no longer the best player in the current Manchester United squad, he doesn't have much evidence that he is still the best among the other players in the team. Ronaldo missed many opportunities to play in Manchester United matches, even Ronaldo did not get a chance when Manchester United lost in the derby against Manchester City.
I checked Ronaldo's stats, he only scored 1 goal in 7 Premier League match. So I'm absolutely sure to say he's not the best at Manchester United at the moment. Ronaldo's performance has indeed declined, but as the player who has played the most for his team's wins in the past, Ronaldo still holds the title even though he has now been replaced.