I disagree with most of this thread. Microsoft must maintain market share at all costs, any additional monetization from tracking or ad revenue is a very distant third to that. It lives based on being the default option. A new launch will bring in new users and help keep existing ones, but it must be seen as successful. So Microsoft needs to port as many of it’s current users over as possible.

Second I think is pruning the nightmare of legacy support. A “new” operating system lets you set a more modern baseline and tell people to buy new hardware in a much more user intelligible way. No having to explain why Windows 7 no longer works on someone’s 2007 laptop that came with it, or come up with a maze of partial support and having to work out what the last usable update was.