Barcelona doesn't have a good financial situation like Manchester City, PSG, and other teams but still, they have a good coach and there are in a good mental situation after winning the La Liga title against Real Madrid while there was a huge gap between Real Madrid and Barcelona and this can have a good effect on this team.
Yes, the problem of financial seems not over yet for Barcelona. But sometimes they are linked with top players, they still signed new players. It means Barcelona has the ability to improve their squad although they don't have much money. Having a good coach is a positive factor for Barcelona, their squad is managed by the right coach. As far as a good coach like Xavi manages Barcelona, they are not impossible to win any title.
But still, if they want to race for the Champions League, I think Barcelona need to hire more and better players to race with other top teams in this tournament.
Barcelona has enough squad to join the race for the title. Even they don't sign many new players, they have the capability to win UCL. They prove that they could win La Liga title, they will never win La Liga if they have bad squad.