Motorizing speed championos cars

I am a Lego fan and programmer/electronics tinkerer. One day i thought about the size of the Powered Up Technic hub. It only has 4 ports, a light and a button and is the size of my fist and hevier than an elefant. If i can get a microcontroller (the main thingy inside the hub) the size of my finger nail for 5-10€ why should i bother whit the massive hub and not make my own! In this will be added servos and motors all in the same little size. Anyways just thought about posting this here, it...