In the U.S., the FAA provides quite a few regulations that specifically forbid the use of autopilot in certain circumstances (e.g. "Autopilot - Minimum Altitudes for Use [0]). More over, the FAA recognizes that extensive use of autopilot functions can degrade a pilot's skills and has issued a SAFO [1] with guidance for aircraft operations and pilot training.

[0]https://www.risingup.com/fars/info/part135-93-FAR.shtml [1] https://www.faa.gov/other_visit/aviation_industry/airline_op...