I don't hate Palmer but his problem was.. he is a 1 position player. Pep would give him time at different positions but he never proved versatile enough and got frustrated.
Lets look at the squad.. other than Rodri, Haaland, Dias and the goalkeepers.. everyone is versatile and can play multiple positions.. so they all share time.
When you're only good in 1 position.. you need to be the best in the world to get time there.
I mean just look at Nunes Left Wing.. but he's proven good enough that he can get time here, there and that's the way. Is he better than Cole Palmer? No.. but he is more versatile and will press and do defensive tackling!