For example automatic speed limiting works off cameras that read speed limit signs. I really don’t think that’s an off-the-shelf standardised sensor. And standardising it would probably hold back how quickly they could innovate in it.
https://www.mobileye.com/us/fleets/technology/speed-limit-in...
So one person makes the OCR component. Another makes the SBC to control it. Another makes the drivers for interfacing with sensors... ect.
Obviously this is too much work for one person. I think it's still worth it though. Maybe not to you, but then again you obviously don't care so you're free to go buy an off the shelf Chevy that you can never fix.