IMHO, this misunderstands the role of theory: it's a multiplier.
Theory directs your practice.
Theory helps you frame, interpret, and improve on your mistakes.
Discussion
It's the basis of all piles
Exactly
Not for everyone. For some "theory" is just talk.
I consider this I'll of folks to be time thieves. I cross the street when I encounter them.
*ilk
I mean literally on the picture shared, in all piles the basis is the same colour, so I assumed that here theory is depicted as the basis of it all
Regarding theory and practice I like the quote "In theory there is no difference between theory and practice, in practice there is!"