We agree with what you say. at least, Xavi has presented 2 trophies this season. although, I am not satisfied with what is shown by Barcelona. it's not about the Champions League, or the trophy, it's about their game as a whole. plus, Xavi as his trainer. I am a Barcelona supporter, but not really entertained by what they show. I mean, Barcelona can't be said to be a pretty solid team as a whole. in particular, early and mid-season. that means, in the next season Xavi has to fix what his team lacks. in a way, bringing in some newcomers.
Anyway, at least we can say that Barcelona is the best team in La Liga. as a fan, I'm happy they won the trophy. however, it is irrelevant to be compared to Manchester City at this point. because, Barcelona is in the stage of fixing their financial problems and at the same time rebuilding the team squad. unlike City, they are financially sound. plus, the performance is on fire. but now, Barcelona is in the stage of heading in a better direction. at least, in the next season Barcelona can be better in competition in the Champions League.
Xavi has only coached Barcelona for the last two seasons, so he still needs time to get a good approach to his team's play especially when the players he has are not of the same quality. Xavi's Barcelona is different from Pep Guardiola's Barcelona, so you shouldn't always have that problem because players and coaches are no longer the same.
I also hope that Xavi can make Barcelona's appearance much more attractive from season to season, but the financial constraints they are experiencing will only complicate the struggle for this team in my opinion. I'm sure Barcelona will improve gradually, so you have to be patient about that.