Granted, this is hardly accurate/scientific - try out a solid hour walk on a treadmill.

A lot of steps for a pittance of calories [based on whatever hand-wavy math it's doing, admittedly]. We're frustratingly efficient. I forget exactly, it was something dumb like half a candy bar.

I've heard people say "you won't outrun your mouth", in this context... and others.

It's true. I've managed to drop my body weight ~half, it happened by controlling what I ate; not how I exercised. When I stopped skateboarding due to an injury, I ballooned. I stopped eating like that over a decade later, I shrunk.

In that time I also got older, moved, and went to college. It's worth considering what's easier/more likely/realistic to maintain