There is a piece of very bad news for Bayern Munich and their fans about their coach, while they're racing hard into Budesligga for the title with Leverkusen and every single point is important for them, it seems Tuch said he is interested in leaving Bundesliga for La Liga and he somehow said that he wants to work for Barcelona. Maybe I'm not right about Tuchel in Barcelona but it was shocking enough when we saw Tuchel even thinking about leaving Bayern Munich.

I'm not really sure whether he can lift Barcelona because I saw his inconsistency in coaching Munich. Because currently Barcelona is having a difficult time winning matches. Plus poor financial conditions.
It would be better for Tuchel to stay in Munich until he can prove that he can bring Munich to win lots of domestic and UCL trophies. Moreover, it should be easier now because he has Kane who really shows excellent qualities as a goal-hungry striker.
It is very risky if he goes to Barcelona, not because he does not have the ability for a coach, but because of the situation faced by Barcelona at this time. Xavi can also actually lift Barcelona's performance, but he struggles because he does not get full support from the club, that's one of the things that makes it very difficult for him to give his best for Barcelona at this time.
I believe there are two things that can afect the decline of a club, the first is because the coach is not good, and the second is because of the situation within the club itself which makes it difficult for the coach to improve in terms of the game. Indeed, at first glance the game is a tactic, but if we look deeper, the role of the club will also be very decisive, especially in suporting all the needs needed by a coach.