Lewandowski is now a player close to retirement and I don't know if he will still perform at a high level for Barcelona. It must be admitted that he was really good last year, but we are all waiting for his performance this year with curiosity. The Polish striker will recover more slowly from possible injuries as he is getting older, which is a negative situation for Barcelona. They should definitely transfer a good and quality striker instead. Barcelona can reach better places with these two transfers this year. I agree.
For the next two seasons I believe Lewandowski is still able to play at a good level but Barcelona needs to find a replacement figure because it is feared about the injury experienced by him.
He can be a distinguishing figure in the team because of the maturity and experience they have so that this is an advantage for Barcelona.
Age can indeed affect speed a little but if Barcelona has a number of creative midfielders it will not be difficult for Lewandowski to play at a better level.
A substitute figure can be used as an alternative because the coach can more easily rotate and I think Barcelona does need the figure next season because they will play in many competencies.