An autopilot in a Cessna can most definitely not take you around the world. Also, autopilots even in a commercial jet keep the plane steady along a route, they don't deal with collisions at all...you could call it "lane keeping" if you want to sue the airline industry for misleading us over a term they created.

Autolanding is not autopilot. In fact, autolanding is not even certified if multiple autopilots are not available to provide redundancy.