If we evaluate the last year, then Barcelona should improve the attack, this would greatly help the team in the future.
I think Barcelona has thought about this because they got tickets to the champions league which is putting pressure on Barcelona to get transfers of new players who can give good performance for Barcelona. if compared with last year I think Barcelona has not had any changes and it's still the same it's just that they haven't been able to find a replacement for Messi who was once a leading player at Barcelona.
Even in the last years, I remember Barcelona had good midfielders but they didn't have very good forwards and their team was not dependent on the forwards they have, they usually score goals by using the midfielders they had.
This season Lewandoski was a good performance but I think if Barcelona wants to hire new players they definitely need to hire a young forward to take his place for the next season.