with circuit python (basically Micropython) from adafruit you can open a screen session to the USB port and get a REPL interface. I wonder if you could set something up to script input and output from REPL (i'm not a python expert). If you could then you'd have a little pipe to the micro-controller where you could enter python and have it execute and return a value. From there you have all the GPIO and other features available on the microcontroller available to you on your computer.
I have one of adadruit's RP2040 boards and use the REPL a lot to talk to other things connected to the i2c bus. For example, controlling servos from a servo board, or getting orientation data from an IMU. Basically, i treat the circuit python REPL like a command line
Sure, in many cases. Depending on the situation, though, it may be no more hassle than any other USB GPIO device, so it's a decent enough cheap solution if you can't or don't want to use a Pi or a similar SBC.
