I sometime wonder if microchip/Soc wouldn't be better if we removed Wifi and USB kind of hardware support that are relying on enormous amount of (bloated) kernel code to perform magic.

Embedded system for having a real purpose of studying and experimentation would rather need a core HF radio transmitter/receiver instead of wifi and the abstract layer for modulation/demodulation digital/physical layer should better be handled in the user space.

USB could be replaced by other bus/hw link that have a simpler state machine and easier wire control. Ex: GPIB.

USB and Wifi have to much states required to function simply.

And seriously, just blitting operation (also usable in cryptography and matrix operations) should be enough to have a decent 2D CPU handling of graphics. Then, with an I2C bus you probably can pilot a chipset to just process the buffers at refresh time and either DAC or push them to a display.

The complexity in the design reflects in the complexity of the code needed to handle it.