That is true but not like the players they got are 20 years old neither, they found some young talent, like Gavi, but Lewandowski is also old, they just had players who were no longer good, Pique wasn't bad just because of his age, he was bad because he was bad, and that's all it is about.
Thankfully, they got some good players and they are doing much better now, and they spent the money in a right way to get the right people on the correct positions. They are still battling injuries a lot, people expected them to be a lot more healthy, but that's fine they are still leading the league and that's what matters, as long as they keep leading the league and win it, that will be enough.
Xavi seems to know what his team needs this season to navigate tough competition. He has good support from the club president and also the management, then he gets the money to buy some of the players that are needed.
This season they really need better left wing instead of just Ferran Torres or Ansu Fati, they are not in a stable form so Raphinha and Dembele are the players who often fill that position. Then in the last few matches, Dembele, who had problems with his fitness, had to step aside and made Xavi try to play Gavi in that position. The result is good, Barcelona can still win but I don't think it will be good forever because Gavi is a midfielder. Barcelona also still need a right back because now Bellerin has also been sold to Sporting CP, then they played Kounde there but it would be great if there was a player who occupies his main position.