An MCU uses less power, is faster to start from a quiescent state and typically is lower cost than hardware intended to support a full operating system. That s

An MCU uses less power, is faster to start from a quiescent state and typically is lower cost than hardware intended to support a full operating system. That said, there are some who flash Pi Zeroes as "bare metal" or no operating system: https://github.com/dwelch67/raspberrypi-zero https://github.com/dwelch67/raspberrypi-zero