I guess Xavi is the happiest person in La Liga because he got what he wanted to get with his team where they know him as a legend and he is coaching Barcelona for the first time his coach in Europa and top teams, Barcelona is in a financial situation in which they can't spend money like Real Madrid and this definitely could affect the results of Barcelona but in the end, Barcelona won the title.
But in the next season, I think Real Madrid can buy better players to have a closer race with Barcelona for the title.
It's not only Xavi, even Lewandowski, is a player who is quite happiest with Barcelona this season. Because he has only had one season with Barcelona, he immediately becomes one of the stickers who is quite aggressive in scoring goals. In making purchases for players, I think Barcelona will exercise the option of selling players first, where many Barcelona players are reported to be released in the transfer window. I think Xavi and Laporta will be able to make significant changes for Barcelona in the transfer window. They have a lot of good quality players and just need to balance their strength by bringing in 2 or 3 players. Additionally they can take the option to sell some players to match their spending.