The problem is that all the coaches who are better than him refused Bayern

I don’t know what will happen next season, but given the fact that Xabi remains, and Bayern does not look like a club that is going to seriously strengthen, there is a high probability that Bayern will fail again next season. Most of all in this situation I feel sorry for Kane, and the fact that the competition in the tournament is growing is only a plus.
From the start, I just highlighted how Bayern Munich is moving in the coaching transfer market this time and as you said, all the good and experienced coaches are reluctant to handle this team starting next season. The reason for the rejection is not yet known, but what is clear is that most coaches don't want to damage their portfolio when the team is not in good condition.
Even though Bayern Munich tried hard to convince all the coaches they were targeting, no one agreed or even tried to ask for a bonus so that the transfer process would run smoothly. The situation at Leverkusen will remain a serious threat to Bayern Munich and I doubt that together with Kompany they can shift this dominance. The rest we will see something that is not much different from this season for next season and Kane looks like he will have to fast for the title again.
I heard that there are conflicts within the Bavarian management itself, but I don’t know the details. But it’s clear that at the level where all the qualified coaches/agents and so on are, there is information about this and no one wants to take the risk of going to an unstable club with unclear prospects. It’s quite sad that Bayern has gone downhill in just a few years and perhaps this process is not over yet.