For people with only one Apple Device!? 2FA nightmare!!!

If you recently updated your account, however, you can unenroll for a period of two weeks. Just open your enrollment confirmation email and click the link to return to your previous security settings. 

Apple doesn’t routinely monitor the discussions. These are mostly user to user discussions.

If you want to, you can send Apple feedback. They won't answer, but at least will know there is a problem or a suggestion for change. If enough people send feedback, it may get the problem/suggested change solved sooner.

Click here to send Feedback    

Maybe I can remove the nightmare. See See Get a verification code and sign in with two-factor authentication https://support.apple.com/en-us/HT204974  Below is an excerpt, but read the whole document. See the bold italics below.

Whenever you sign in with your Apple ID on a new device or browser, you'll confirm your identity with your password plus a six-digit verification code. There are a few ways you can get a verification code. You can use the code displayed on your trusted device, get a text or phone call, or generate a code from your trusted device [see the additional information in the article].

A trusted device is an iPhone, iPad, or iPod Touch with iOS 9 and later or a Mac with OS X El Capitan and later that you've already signed into using two-factor authentication.