Barcelona has hired an experienced coach like Hansi Flick. And Barcelona probably won't buy any new players this season. Firstly, Barcelona do not have enough money to buy players. Secondly, Barcelona now wants to build a squad based on youth, so that Barcelona can get a long term service from these players.
Barcelona have a lot of talented young players in their squad. Forwards include Torres, Fati, Yamal and Roque. Each is a talented and promising player. Everyone has the potential to become a star player in the future if nurtured properly. The midfield has talented players like Gavi, Pedri and Lopez. Perhaps Hansi Flick's main and only goal in the coming season will be to improve the performance of these young players. This is why the Barcelona management made Flick the coach of the team.
I agree with your opinion, with Barcelona's current financial situation, it is definitely impossible for Barcelona to buy players. Because this could definitely worsen Barcelona's financial situation. For this reason, Barcelona chose the most effective shortcut and did not cost too much. The shortcut is to contract a new coach, namely Hansi Flick. Because by bringing in an experienced coach like Hansi Flick, Barcelona will definitely be able to maximize the performance of the players it has. The reason is that Hansi Flick already has quite extensive experience in the world of football coaching. He has coached many teams during his career as a football coach, he has coached big teams such as Munich and the German national team. So you can be sure that with the experience he has, Hansi Flick can definitely make Barcelona perform optimally even with the current players.
Moreover, the majority of Barcelona players are young players. It is certain that Hansi will find it easier to shape the characters of these players so that they become better. But even so, the toughest challenge that Hansi Flick will definitely go through in Barcelona is a process that will definitely take a long time to show Barcelona's best performance. So in essence, in his first season coaching Barcelona, we certainly shouldn't expect Barcelona to immediately show a very good performance. Even though it's true, Barcelona currently has a lot of young talent (as you mentioned). However, this still cannot make Barcelona's performance immediately good in the hands of Hansi Flick. Moreover, next season the competition in Laliga will definitely be even tighter. So you can be sure that this will make it a little difficult for Barcelona to shine quickly under Hansi Flick.