We paid 60-70M. For us, that's a headline signing and we kinda expect / need him to be great. That's an "us" problem rather than a Nunez problem but still, it is what it is.
Nunez has his upsides but his touch / passing / crossing is a little too erratic for my liking to play out wide consistently. I suppose these days you could level the same accusations at Salah but we know why he's in the team.
Again, most of what I'm reading in this thread ("he's a handful" and "he occupies defenders") is classic excuse making for a player that simply hasn't lived up to expectations.
I think this is all fair, I'd elaborate on the final point though. In his worst form, he is still making life a nightmare for the opposition and that creates chances for him and for others (either directly or by pulling people around in their systems). In his best form he is a lethal & potent striker.
I'm quite happy if we have an attacker who on their worst day is still making chances for themselves, for others and leaving the opposition in tatters. There are many many top strikers who on their worst days are complete passengers and anonymous. That is at least one thing we haven't had to contend with.