I use older devices for music and pics, instead of storing all that on my new iPhone or iCloud - because that is what I choose to do, and am barraged with the 2-factor everytime I even try to use them - despite the fact said devices are already on my trusted list, & now to find out THIS
"Can I turn off two-factor authentication after I’ve turned it on?
If you already use two-factor authentication, you can no longer turn it off. Certain features in the latest versions of iOS and macOS require this extra level of security, which is designed to protect your information. If you recently updated your account, you can unenroll for two weeks. Just open your enrollment confirmation email and click the link to return to your previous security settings. Keep in mind, this makes your account less secure and means that you can't use features that require higher security."
[Edited by Host]