TouchID > FaceID
For example, my wife receives alerts throughout the day that need quick responses. Lets say her iPhone 6S is lying flat on the table and receives an alert. She can tap the notification, then home button, and she'll be directly into the correct app screen with 2 ultra quick taps. Same scenario with an iPhone Xr or Xs on the desk - tap the notification, then either pickup the phone and wait for FaceID, or tap twice then type in your PIN if you don't want to pickup the phone. It doesn't seem like much, but when speed is important, and you're doing it 20+ times/day, the difference is very noticeable.
Another real-world example is on my motorbikes. I'm constantly using my phone navigating and exploring. With helmet on, FaceID doesn't work, so you're forced to type in the PIN which is bloody maddening.
Another example is you can have up to 10 touchID fingerprints, but only 2 faceID's. So in reality you have 1 standard and 1 with sunglasses, but then your partner can't unlock the phone quickly to take pictures or make a call.