He dribbles well and has normal first touch for a City player..
What he lacks is ability to hold the ball during the pressure..
For a midfielder that's the big issue, but I remember Cancelo had same and even Mahrez, they were constantly loosing the ball, if you remember those 2019 / 2020 games...
City isn't a team where you just run and pass the ball back or upfront as soon as you get it, or receive the ball in the motion and accelerate even more. In most cases, you need to spend a little time with it and that's how you dominate the possession. If everyone passed the ball and just moved around, we wouldn't be able to survive man-to-man pressings and etc.
So Nunez gets ball, opponent engages in a physical duel and you know he will loose it, the only option is to get rid of the ball as soon as possible, but that's not the level, that is acceptable for a City player..
That's something I didn't like about Phillips.. But Philips couldn't dribble as well and had awful first touch.
So he needs to get stronger, otherwise he won't make it here, especially as a midfield player. Maybe when you are a winger, you can play like that and that's how Sane used to play and he did ok. But today even our wingers hold the ball and that's something Jack is best at, not even mentioning Bernardo.
Learn to hold the fucking ball mate, otherwise you are liability for a team, that has elite opponents and needs every player to be up to standards.