I always felt that as technology has advanced, it would slowly keep us shade tree mechanics out of the engine bay. Thirty years ago a good set of tools and voltage tester was about all you needed to get by. Today you can still use your tools, but an understanding of all the different computer systems is a plus if you even can tackle a engine issue. Now a good code reader is needed in your tool box. Plus you might have your hands tied unless you want to void a warranty. It comes down to you might only be able to change your oil and do a few simple maintenance issues like filters, etc.
I have basic automotive repair knowledge which In my situation I can do everything to my old car except rebuild an engine, transmission, carb without some help. That is why I like my G body because I can repair most of my mechanical issues.
It would be nice to have a modern bare bones kinda car but I fear those days are long gone and like it or not, technology has locked many of us out of engine, etc. The answer is just to always keep an old car in your fleet and God willing you will be able to work on a car for as long as breath is in your body.