So first off, kudos to Apple for finally making it relatively easy to disable Touch ID or Face ID on an iPhone: when the phone is locked, press the power button 5 times in a row. So if you are entering a country, I recommend doing this before you get to customs or any security check point.
But unfortunately courts have recently been eroding the Fifth Amendment by ruling that people can legally compelled to give up their passwords. And woe to those who forget them. And that’s just in the US. Some other countries might even be a bit more draconian when it comes to password extraction methods (i.e. the so-called “rubber hose” method).
That is why it is imperative that all devices which store sensitive, personal information must have a separate duress password. This allows the person to “unlock” the device, but only into a second data store. It would need to include enough dummy data so that it appears—or at least provide plausible deniability—that the person is indeed complying with the order. TrueCrypt (and its successor, VeraCrypt) included a hidden volume feature for exactly this reason.
I don’t expect to ever need such a feature, but having it would provide peace of mind, and is a good way to keep the balance of power between the government and the people.