I don't think he want to leave personally.
I guess it's his last chance for a final big pay day. Although I'm not quite sure where he'd go.
City seem like the most likely option. Obviously they're in the market for a striker and Lewandowski is probably the best in the world right now. Pep has worked with him before too. But do they really want to go for a 33 year old no matter how good he is? With striker being their biggest weakness you'd think they would want someone who can fill that role for years to come.
United aren't looking to get a striker right now. They've got Cavani, Greenwood is coming up and they may go for Haaland next season.
Chelsea just bought Lukaku.
Liverpool could be interesting since he's worked with Klopp in the past. But Liverpool have spent a lot recently and they don't seem to go for those really big price tags.
PSG don't need any more attacking players.
Barcelona are broke
Real Madrid are struggling financially as well but also are looking to get Mbappe (how those two things can co-exist I'm not quite sure but that's Real Madrid for you)
No club in Italy could afford him just now