I've flown "right seat" (not pilot) a fair number of times. Air traffic control interacts with the pilot quite often and at fairly unpredictable times. This requires the pilot to be alert and respond promptly to a request or direction from air traffic control. If the pilot doesn't respond promptly, air traffic control repeats the request with more urgency and goes into the "lost communications" procedure if there is no response.

tl;dr: aircraft pilots generally must be attentive. Tesla drivers on "auto pilot" - not so much.