Not trying to give the glory to Flick for what he has achieved so far since he took over as the Barcelona coach but looking at the players that was on the Barcelona coach during the time of Xavi I don't see much difference between the current players now and then because Barcelona is still in financial crisis but the current manager is managing the team and he has used same players to achieve a great result in the team.
You think Flick didn't do much compared to what Xavi did but I think it's because Real Madrid didn't do well last season is why they made it out. If Real Madrid was really the way they are all this while? Believe me the way they were fighting and all others way to make it to be first team on the table, it would have been impossible for Barcelona to win Laliga last season but Real Madrid lost its 3 El clasico, there was nothing to show off about their performance.
If they are that fabulous and team think they have improve, they would have done everything to win the Champions League but look at Real Madrid mistake from beginning to the end of their season, they lack importance of defenders, they were losing too much that it was affecting everything they were doing. Not to forget about Mbape adaption in the team, his first two month was chaos, he was struggling to make goals, someone that was once the best in France. This is why I think Barcelona aren't that different.
You should give credit to a team that has performed well Barcelona performance this season was good you should not try to discredit what Barcelona has achieved whether Madrid was inform or not the way and manner that Barcelona won the league was fantastic you should not forget that three different teams where topping the laliga table with at least six points at different times and eventually Barcelona won so they should be commended