Mayfield Robotics is making a non-flying version of this, called the Kuri: https://www.heykuri.com/

It is a real product, founded by a bunch of robotics people from Harvey Mudd.

The camera angle seems like it could be... problematic, though.

Also it doesn't look like it has the capability to follow me in even most sedate urban environments. I mean, I'm not asking for stairs, but that thing looks like it'd have a hard time with a sidewalk crack.

Both those problems could probably be solved by making it bigger.