Compute is so God-damn cheap these days that it often makes sense not to fabricate a custom ASIC, just emulate what the ASIC would do with a microcontroller. For example, in the case of people who build new, retro style computers, often a microcontroller or two are handling I/O to and from the peripherals like the screen and keyboard. Like there might be an Arduino or Pi Pico generating a VGA signal instead of a dedicated CRTC (because no one makes old-school CRTCs anymore). I just think that's wild, especially when the I/O controllers are more powerful than the main CPU itself (as might happen with a Z80-based system).
