With a squad like Manchester City, Nunez might have scored a lot of goals. Not to say that the Liverpool squad is weak. However, since Sadio Mane left the team, Liverpool's performance has completely collapsed. And their performance was very erratic. Because of this, the team has not consistently performed better than Nunez. However, in the last few games of the season, Liverpool played very well and their performance was stable. Therefore, it is expected that Liverpool's performance will not be irregular in the next season. At the same time, Nunez will be able to score a lot of goals if he gets enough support from his teammates.
Darwin Núñez is a good striker, but he has failed to adapt perfectly to Liverpool's attack. Nunez often seems to miss good opportunities when he has the ball, that's because his finishing is sometimes poor. Klopp has given him a break and trained harder, but Darwin Núñez hasn't changed much.
I believe Darwin will be better in his second season at Liverpool and he shouldn't be a bad signing for Klopp. Darwin has quality, but maybe it's true that he should get more moral support from his team-mates.
This season has not gone well for Dawin because indeed he even has problems in terms of finishing but indeed there are still some conditions that can be forced of course this season.
He has to do his best next season because indeed this has to be an answer for him because if this continues then indeed he can be considered a purchase even if it's not too bad but still for a high price it's a failure.
He really threatens a lot with the speed he has always shown this season, it's just that, as you said, for finishing he is really bad because he seems to be struggling, especially with his emotions that are still overflowing, he must be more able to control it at this time.
Hopefully next season will go according to what Klopp and Liverpool expect especially they are unlikely to add players to the attack line in this transfer and focus more on the midfield.