Robert Lewandowski is of course one of the greatest strikers now. He is getting older but his performance improves more in time. I think that he is better than last season now for example. He can break a new goal record in the Bundesliga if he goes on like that. Bayern Munich are really lucky to have him but he seems likely to leave this summer also I think. Actually it will depend on the offers for him. If he gets a really satisfying offer from another big club, then maybe he would make a change in his life from now on.
Bayern is trying to renew Lewandowski contract and I don't think he wants to leave the club. He is doing fine there, a change will not make him better but may end his career. AFAIK PSG is interested in his services which might be interesting especially if Mbappe will leave the club and since Messi isn't top right now.