And that still leaves aside tricky things like construction sites, double parked cars, etc.
Commercial airline autopilot has a lot more straightforward job: at normal operating altitudes there are no animals to worry about, no construction or other unexpected obstacles, and few other aircraft all of which can be essentially guaranteed to be squawking transponder codes of their own, and they still are mandated to have two pilots in them at all times. This is not because airlines like it- look how fast the flight engineer disappeared once flight management and navigation software became sufficient. It is instead because airlines have learned over the decades, from a lot of blood, that sometimes you need to have a pilot ready to intervene RIGHT THIS INSTANT, not 3 minutes from now when you've regained situational awareness after zoning out for a bit- and the AF447 disaster shows that they are right about that. And the only way to make sure you have such focus and alertness over many hours is to have two pilots, so they can trade off the responsibility of maintaining SA.
And that's a much easier problem which has been actively attacked for decades.