lewandowski seems to have never played in the europa league before because he always played in the champions league with bayern munich and maybe this is the first time for him to explore the europa league competition with barcelona. There is no doubt about Lewandowski quality because he has been able to make a big contribution in every game he has played with Barcelona this season. So, for this season, the fans hope to see that Lewandowski is able to present a trophy for Barcelona.
Lewandowski has been motivated to tries to add his trophy collection to his library, Uefa Europa league is one he doesn't have which I think is a big desire to create many goals to Barcelona. But, the age factor is one condition he must think if want to continue in europa competition because there is a opponent that has golden age player who can be as competitor. Barca also have the attacker who can replace him any time if can give a contribution like Dembele, Raphinha, Depay and Torres.
Lewandowski plays very well after that for 1 or 2 seasons, and then he may retire from football. Having youngsters for Barcelona is an advantage for the team because they have learned a lot from Lewandowski right now. Moreover, when Lewandowski leaves the team, they do not have to wait long to fill his place. I don't think it will gain extra motivation to win the Europa League Cup for Lewandowski. He would get that motivation in the champions league, but I'm not sure if the Europa league will provide the same motivation.
I agree that a team has to have young players because that will make the team have these players for many years and so the players, when they are together for many years, already have a good synchronization on the field, and it is easier for them to play with each other others, the passes are more precious, but in this case of barcelona I don't see them having young players who are at a level at least close to Lewandowski which certainly means that if barcelona does not have Lewandowski then they will not be a great team, barcelona needs to become a team in which there are many good young players who are at Lewandowski's level
one of these days watching one of the barcelona games, i started to see how much selfishness the barcelona strikers had that i kept thinking that they really wanted to go far in the champions league playing that way, and now they are in the europe league and I don't see them as the favorites to win the europe league, they still need to improve some things to be able to win the champions league or the europe league