Yeah, this is a meme that circulates in the $TSLAQ world, often appearing alongside shrieks of "Panel Gaps!". There really isn't a source, Super Cruise just isn't very available in public yet (just a tiny handful of cars have it, with probably less than 20k users).

The core of the point is generally that Tesla AP is deployed as a hands-on solution, requiring regular steering wheel input (just twisting the wheel a bit), where GM ships this in cars with cameras pointed at the driver (Tesla has them too now, though the wheel nags still exist) that take the entire monitoring load. That makes it "hands free", and therefore better. This is often combined with a conflation of "hands free" with SAE L3 Autonomy (which isn't correct) to try to emphasize the point, skipping the fact that the hands-free areas are limited just just a few hand-vetted highways. All Tesla would need to do to compete with that feature would be to implement the same geofencing, basically. But that's not where they're aiming.

I mean, in the real world, AP is pretty amazing and SC is mostly vaporware. My car took me 429 miles last Thursday and the only input required beyond wheel nags was some editorial differences I had with it about proper lane selection (and even then, I was only right about 60% of the time).

what areas can FSD drive in?

I don't even have the FSD beta but my autopilot can turn on anywhere there's lane lines basically.

Apples don't have orange skin.