My sister uses Windows 10 in her one-person accounting business. The performance of everything she does is fine as is. The main thing she needs is stability, and the last thing she wants is any kind of upheaval of her computing environment, the processes she uses every day, the software she uses every day, etc. She has all kinds of workarounds for flaky software she has to use every day, and figuring out new workarounds for new flaky software is not something she wants at all.

Microsoft would do much better IMO if it focused on reducing problems and increasing their ability to support users rather than adding features and constantly changing the way people have to interact with their computer. A lot of people simply don't care about that crap.