One scenario I can think of: When there's an occasion where you want to give them unlimited time, but you don't want to disclose the code and then later have to reset it to something new. Or you want to delegate permission to a babysitter.

You just give them the doohickey and ask for it back later. (Cloning the NFC tag is a much harder job that remembering a PIN.)

Apple Screen Time will occasionally stop blocking applications, allowing the child account to use them without restrictions.

Other drawbacks include only a single period of "down time" per day. There is also an inability to totally block applications; the closest analogue is to set a maximum of one minute for the website or application.

Screen time blocks are terrible

I use them myself to limit some websites that waste my time

It is way too easy to click on 1 more minute, or 15 mins or ignore for the day

The only way to really block sites is to add them as adult websites and turn on parental controls

But can’t do that with apps