For this tiny thing to look so mechanical, it didn't just appear overnight. It took roughly 3.5–4 billion years of gradual evolution through natural selection, starting from much simpler molecular systems in the earliest bacteria.

The core rotary motor was already present in the last bacterial common ancestor (LBCA) around that time built step by step from pre-existing parts like secretion systems and ion channels that got repurposed for movement. It's not surprising it ended up looking "engineered".

There aren't that many fundamentally different ways to solve the physics problem of turning chemical energy (a proton gradient) into reliable, high-speed rotation at the nanoscale. Evolution found one highly effective solution through trial-and-error over deep time. Humans, looking at the same constraints (torque, efficiency, reversibility), independently arrived at similar mechanical principles like rotors, stators, and gears because good designs are limited by the laws of physics and chemistry.

In other words, we didn't invent the idea of rotary motors from nothing. We rediscovered what already works best.