Alright. If that's what you want to nitpick here

The average adult (in the US) can ride a bike, whether or not they ever actually do is a different matter, but the majority of us learned how to at some point, and there's a reason "it's like riding a bike" is a saying.

From being able to ride a bike to being able to ride it a reasonably long distance just takes time and work to build up to it, which is what he said.

Now a lot of people won't put in that kind of work, but that doesn't mean that they can't.

I'm fat, I won't sugar-coat that. In a couple weeks when it warms up a bit I'll hop on my bike, and I'll probably manage around 5 miles, and by the end of the summer I'll probably work my way up to around 15 miles, and I'll still be fat. I do this pretty much every year (and worth noting, I didn't even learn to ride a bike until I was in my 30s)

There are parts of the world where damn-near everyone gets around on bikes, they don't have some sort of unattainable genetic advantage because they grew up in Amsterdam or whatever that gives them some "dormant athleticism" that Americans don't have, they just ride bikes.

The average adult can ride a bike. They just don't or won't.

Bruh you seem really stuck on this idea of "dormant physical athleticism" whatever that means.

Let me break this down for you, the human body has muscles, these are like motors for moving bits of flesh and bone around. Like motors, the amount of physical energy they output changes based on the energy that gets input. Since humans don't really have control of the chemical energy flow to these muscles, the way you can change that is by pushing these muscles to their limits, and as you keep doing that these limits start increasing.

Its really quite awesome, because unlike most things in life, your muscle gain directly correlates to the amount of work you put in. Its one of the few things you can directly control!