The actual answer, there is no reason to switch. The vast majority of users do not care about Linux or why they would want to. For us there are lots of benefits and things we enjoy about getting away from Windows but for them "why?"
I will object on this one. Even if the majority of user does not care about privacy they do care about ransomware , viruses, speed of the system and in my opinion Linux / BSD is secure, fast and speed remains after time not like Windows where I felt that after 6 months I had to reinstall to get a performant system. I guess it is all about convincing your family and friends about those benefits.