A lot of people don't update or don't update immediately.
[1] https://9to5mac.com/2020/06/19/apple-says-ios-13-is-now-runn...
[2] https://developer.apple.com/support/app-store/
[3] https://en.wikipedia.org/wiki/IOS_version_history#iOS_13_/_i...
Still you have options, load windows in a vm (hint: ms releases a fully functioning vm image every month that works for all major hypervisors). Install iTunes and you’re all set.
1) it's really annoying to have your crap moved around without being asked
2) it's often the only way to retain control of your device.