I have no doubt this will be an unpopular opinion, but I think there’s a good chance that there’s a decent player in there somewhere. He was derided here as having a poor first touch, not a footballer, competition winner, etc, after what seemed like only a handful of appearances for us at a time when there was apparently a lot going on in his life.
He has obviously struggled to make the transition to the PL, but occasionally showed glimpses of something better. In the WC he looked a different player, good first touch, pacey and even skilful.
If the club do not intend to buy another CF, then of the trinity of him, Ulloa and Slimani, I would keep him and sell the others unless we can get at least 20m, in which case we need to buy a replacement.