Users can enter the destination before being picked up. I've had drivers cancel before arriving, so I usually wait to enter the destination until my seat belt is buckled.
Interesting! Is this just to get a fare estimate? I don't think I ever noticed this feature in the app back when I used it.
This is especially true when the address contains difficult or uncommon words like Sycamore or Cheswycke, which I'm pretty sure I'd screw up writing, and I'd guess that others would as well.