Today my iPad automatically updated its OS to 14.2 and it shows a prompt from Apple ID Security to enable two-factor authentication.
The message mentions that "Some iOS features require two-factor authentication", but I could not find which features exactly require it. The Apple's support page Two-factor authentication for Apple ID tells me what this two-factor authentication is and how it is important, but it doesn't say which features of the OS require it. There is only the same vague phrase without any details:
Certain features in the latest versions of iOS and macOS require this extra level of security, which is designed to protect your information.
You need two-factor authentication to use certain features that require improved security.
I'd like to know exactly what features of iOS require two-factor authentication.