Off topic. How did these underpowered, skinny tired (but light) vehicles perform so well in the mud?

Have you ever watched videos of Model T's zooming down primitive mud filled roads and not missing a beat. They were underpowered, rode on skinny - damn near bicycle tires and although light could zoom with the best of them. How did they do it? It goes against modern convention but it worked. What is the code to this kind of mobility across muddy, broken ground? They knew something we've missed.

I look at these kind of videos and wonder how much of what is common in my area for off road mobility is just fashion over substance.

Not riding on at least 33's?  You better turn around and not even try it.  Better if you're riding on 35's!  Less than a V-8?  Don't think about it.  Tacoma boys not allowed.

Kinda weird.

Anybody do a little off roading know the answer?