Elk board has two processors:
1- Allwinner H3 micro-processor (1.2Ghz of speed) holds the decentralized nodes services syncing with the network and process user requests.
2- STM32f411 micro-controller (100Mhz) which is programmed by the user using our simple Arduino like SDK interface connecting your hardware sensors, actuators and more, taking actions once the Allwinner processor sends back responses to the requests.
While ESP dev boards are one of the powerful micro-controller boards in the market but it really takes time,effort and sure resources to run both decentralized services and user sketch. Running decent. nodes out of the box over a micro-processor is much more easier than re-inventing the wheel and building a light nodes over micro-controllers.