Less likely to develop carpal tunnel

Maybe, but you can still mishandle your wrist heavily and you can cause shoulder problems and other such things. At the end of the day, its about using your body right. If your posture is correct, if you settle your wrist in a proper position and don't force it, you'll be fine. And its really easy to -> when you feel pain or discomfort just fucking listen to your body, rest immediatelly/never play over the pain, and fix the setup/position that caused the pain in the first place.

As for wrist rests they are shit. Your wrist should be in a perfectly rested position with a normal mouse pad. The wrist rest MAY be useful if you have a particularly weird angle into your desk -> maybe. But I wouldn't rely on them.