It is based on the brain, but only in the loosest possible terms; ML is a cargo cult of biology. It's kind of surprising that it works at all.

It works because well, its actually pretty primitive at its core. Whole learning process is actually pretty brutal. Doing millions of interations w/ random (and semi-random) adjustments.

I think I've fallen into the "it's just a very fancy kind of lossy compression" camp.

Honestly once you understand maximum-likelihood estimation, empirical risk minimization, automatic differentiation, and stochastic gradient descent, it's not that much of a surprise it works.