Then why does going faster also make it easier to balance on something without steering, like a snowboard?
My assumption is that when you’re standing still relative to the ground you can fall in many directions, but once you start moving momentum limits the directions you can fall to the ones in line with your motion. So the faster you’re moving the fewer directions you need to worry about.
I’ll admit, I don’t know much about snowboarding, but what I was trying to say is that it’s generally easier to balance at higher speed, even if you can’t steer it.
Imagine stepping onto a frictionless surface, without being able to push off the surface you would quickly lose balance. But if you had a running start you could more easily keep balance as you coast along.
I’m not sure if it’s as simple as response time, I would imagine it could even work with something inanimate. Stand a box on its edge and it’ll fall right over, but slide it on that edge and it can balance for longer.