Here's a simpler view.
Last season Liverpool finished 5th with 67 points, 19 wins, 10 draws, 9 losses, 75 goals for, 47 against, + 28 goal difference 0 silverware
Nunez made 29 apps, 9 goals, 3 assists and was involved in 16 wins and 6 losses
This season Liverpool are 3rd (and likely to finish there) with 75 points, 24 wins, 7 draws, 4 losses, 77 goals for, 36 against, + 41 goal difference 1 silverware
Nunez has made so far 33 apps, 11 goals, 8 assists and was involved in 21 wins and 3 losses
In other words the team is better and Nunez has been better. Liverpool are almost certainly back in the CL, are still involved in a title charge (eventhough tis most unlikely) and has won a nice piece of silverware. Tis a good season and it's a shame to tie ourselves in knots because one of our forwards isn't everything people want him to be. He is effective and as much part of our improved form this season as any other player in the team.
I sometimes think our fans dislike Nunez because he gets mocked by the opposition so much. But he is still a very good option to have, even if his form has tailed off at the latter end of the season.
Just for comparison, Kai Havertz, who is currently being raved about, has 24 apps in the league this season, 12 goals, 4 assists, 25 wins and 4 losses.
It's funny how fortunes change and opinions too. Nunez is plenty good enough, I would prefer to get more attackers than start the whole 'replace a forward I don't like' game.