They bought him with plans to build him up as an important player of the team. Mane left. Firmino lost his form. Salah is more than 30s. So Liverpool are preparing to replace Salah by Nunez. They want to use him a main striker and get main goal resource for the club from Nunez.
But for now, Nunez is just a new player of Liverpool and he needs to contribute more, build up his role there.
The EPL is tougher than other leagues, including the portuguese league. There are not many players who can adapt quickly. Nunez also included, he needs more playing time for adjustments. But it's a pity that he has already got a red card, for poking the crystal palace defender.
It seemed to be a small mistake that made him miss 3 games.
At a young age I agree he is a player who will continue to develop. From the start of the season I thought that Liverpool and city would dominate the EPL, but it seemed that at the beginning of this league my guess was wrong.