Ferran gets done dirty here. Yes, not good enough for Barca, but nowhere near the meme player he is made out to be. His terrible performances have been at LW, which he has never played in his career. In his favourite position, out on the right has been not so bad, best crosser of the ball in the squad.
Compared to João, they were both best at their first clubs, but Ferran was in a tougher league. João hasn't done anything outside of his first club, whilst Ferran was somewhat okay for Man City.
International football, Ferran has been far better than João. Ferran has been poor for 1 club Barca. João has been poor for 2, Atleti and Chelsea.
Honestly, there's not much difference in quality between the two. As a result, we should not be considering João in any way shape or form.