"Bare-Bones" Slant

Hello, all. Just a bit of curiosity here...

I dug around the search bar on the forum and didn't see much pertaining, directly, to emissions operations or the necessity of the add-on's the government required for motor vehicles in the 70's forward. Most of what I see under the hood is a load of wiring, sensors, and quarter inch hosing, most of which I have no clue what it means or does. I've read the service manual and the faithful "Work Bench How-To" and I have a firm understanding of how the motor works and the basics of how it's put together. Now I approach my question(s):

How much of the emissions tech is necessary for this vehicle to run and is most of it over-kill?

What would it take to simplify this machine?