It's one of the option during the first experience configuration of Windows 10. If you had another browser installed, one of the toggle is : do you want to use

It's one of the option during the first experience configuration of Windows 10. If you had another browser installed, one of the toggle is : do you want to use Edge as default browser. Hopefully, people that feel that strongly about their browser choice don't just use "Express settings" when installing a whole operating system.