Many people are not aware or don't care enough about ankle mobility (flexibility and strength) eventually ankles are complicated and delicate, and better ankle mobility prevents injuries and enables us a broader range of motion in our basic daily movement like walking, standing, kneeling down, falling, jumping etc.

Our mobility (ability to move) is something we take for granted when we have it, and only understand how precious it is when it's gone or when we're injured, that's why working on basic movements has such a high value for longevity.

Pistol squat
Pistol squat requires ankle mobility
official Active Flexibility page
Active flexing hill