You put aside the fact that Bayern don't want Ronaldo at Bayern.
And with this it will actually become clear that they can't bring in Kane as you say there are still many options and it's not just Ronaldo. Bayern still adhere to their philosophy and Ronaldo is not included in theirs.
Bayern still have to find a striker but definitely not Ronaldo.
Bayern Munich always wants young and talented strikers, which means Bayern Munich would prefer to get a young striker who has become a star and is famous in the football scene. Even though it is very easy to conclude that a striker like Lewandowski who is still very productive in scoring goals is also willing to be released by Bayern Munich, so I also don't think that Bayern Munich would want to look at Ronaldo to be placed in his team at this time.