Apple has released watchOS 7.4 for all supported Apple Watches (dating back to the Series 3), and its headline feature involves unlocking your iPhone while wearing a mask.
With the update, your watch will be able to unlock your iPhone when Face ID detects you’re wearing a mask. If you’re wearing your Apple Watch, Face ID won’t bug you for a PIN when it fails to see your entire face (so long as your iPhone has iOS 14.5, of course). This should help speed up the process of getting into your phone while wearing a mask, especially if you’re trying to use Apple Pay (read: Not A Fun Process with iOS 14.4).
In addition, watchOS 7.4 includes EKG support for Australia and Vietnam and support for AirPlay in Apple Fitness Plus.