I am convinced, had he gone to Man City, he would be considered a great player.
Firstly, they wouldn't have wasted him in defensive midfield for 3 or more seasons. Since Solskjaer was sacked, Fred has been playing further up the pitch and has managed to go joint-second for assists for all CMs in the Premier League (5). All of them came after Solskjaer's sacking, so 28th November 2021 onwards. He must have one of the best assist to game ratios as CM in the league, possibly even the best. 5 assists in 14 games as a CM.
At the moment, he has a goal contribution (assists + goals) of 1 to 2 games as a CM. That is great.
Secondly, he suits a pressing team far more than what Manchester United are. Someone posted a table on here a few months back showing Fred as our top presser, but the gap to second was ridiculous. He was like 150 ahead over the course of the season up to that point.
I feel he is a player that is going to go down as one who was wasted.