I don't think Barcelona is in too much of a crisis. If Barcelona does not buy a new striker this season, they will not face any problems. Barcelona's forward Lineup is still strong enough. And their gameplay is excellent. Their only weakness is defence. On the other hand, if Real Madrid cannot add any new talented striker, and if Benzema cannot maintain his form, then Real Madrid's performance will be severely reduced.
Xavi will probably earn some money which he can use to transfer new players in their preparations for next season. Barcelona's performance has been much better than before but of course they still need some improvements, especially in defense and attack. Ansu Fati, Aubameyang, Ferran Torres are still reliable next season but Barcelona still need more players than just them.
Memphis Depay, Luuk De Jong and Adama Traure are unlikely to play again at Barcelona next season because they are rumored to be sold or returned to their respective teams. So of course Barcelona need a replacement especially Barcelona will be eyeing the title next season.
If Barcelona want a faster result then of course getting new players is a must, but if Barcelona are not chasing titles too quickly then I think it would be better if they try to play with academy graduates. Because over time, of course, young players will develop better if given the opportunity to play, considering Barcelona's finances don't look good even for signing Lewandowski, Barcelona still has financial constraints.