[dsfyu404ed]

If you don't want to do complex diagnostics that kind of stuff is unnecessary for the overwhelming majority of repairs on the overwhelming majority of vehicles.

I think you're bother over estimating the complexity of modern vehicles and under estimating the simplicity of old ones. Back in the carburetor days people were complaining about vacuum line spaghetti to run the emissions system. People always complain about new stuff.

The reason new stuff is harder for DIYers to work on is because there isn't yet a body of knowledge on how to work on them without all the stuff a shop had.

[porknubbins]

As someone who had only ever done oil/battery change level auto work this was surprisingly exactly my experience replacing a bad knock sensor in my truck. OBD tells you the problem (a sensor is out of voltage range) and youtube tells you how to fix it step by step. At one point my family saw the intake manifold on the floor and thought the car was never going to run again, but its really just plugging or unplugging things from a big computer now. If you can write software you can do (most) auto work.