As long as the performance of the older star players at the big clubs doesn't decline, there is no problem. Think of Ronaldo, Luka Modric and many other star footballers. 36 years old is a high age for football, of course it is difficult for them to perform fully, but when we look at the situation of the teams, we can see how valuable experienced players are.
I think he still has the potential to do very good things for his team for at least 2 more years. I am sure he will continue to be successful, he just needs to avoid injuries
In certain conditions, experienced players have a big influence on the pattern of play and it will usually be much more mature because in terms of experience they have been tested enough. Barcelona has players who are able to provide measured passes for Lewandowski so it will be much easier for him to achieve good performance even though he is no longer young. What needs to be done is how to avoid prolonged injuries so that Lewandowski can play at a good level in the next two seasons. If Barcelona wants to find a replacement, maybe both of them can be played alternately so that it will be much better because they have options when rotating.I think he still has the potential to do very good things for his team for at least 2 more years. I am sure he will continue to be successful, he just needs to avoid injuries