Don't get me wrong, I'm sure that Kane will win something at Bayern if he stays. It would be almost impossible not to.
But his career to date should at the very least cause pause for thought that if you want to be an elite winning club, it's worth playing one of the other ways... and at least being prepared to give other patterns of play a try, and developing other options.
What absolutely does my nut is playing Kane for full matches in every game. It's cost England, and his clubs, trophies. When his legs are dead, he's shit. Recognise it, and do something else. Or be a perpetual loser.