Age is a problem for Lewandowski and his performance is starting to decline, but in my opinion he is still worth keeping for the next season because he still deserves to play at a high level. But Barcelona is reportedly also targeting another striker to support Lewandowski. I think this decision is quite right because it could be an alternative between the two. However, so far we have not seen at all who will be the replacement figure for Xavi, because whoever will be the coach will really determine the game scheme implemented and the compatibility with the existing players so that Lewandowski's role will really depend on the new coach.
It's true that Lewandowski's performance is influenced by his age. We can also see that in every match they don't just rely on one player but they have to work as a team to be able to score goals. If Barcelona wants to bring in another new attacking player, they must be younger than Lewandowski and have skills that are probably almost the same as Lewandowski.