Yep, those were the days, when you needed to be a REAL MECHANIC to work on a car. These days working on cars is rediculously simple, as the failures are either old-school (brakes, steering linkage, shocks, etc.), or new stuff where the computer points you right to the item needing replacement. Plus you have YouTube to tell you, in 10 different ways, how to do the repair. Too damn easy now, doesn’t take any special skills to work on one’s own car.
I do understand what you are saying and YouTube videos can be incredibly helpful. I am not sure that could call myself a “real mechanic” but other than some minor transmission work that needed special tools... I have never had any vehicle that I own worked on by anyone else.
I have owned vehicles from the 1940s on up. And have worked on tractors and other equipment that was quite a bit older than that. I have a collection of magazines, and manuals that an old mechanic gave me when I was young.
The first cars and trucks that I owned with computer controls... you used a paperclip to get them to blink out the codes to give you a clue what the problem was then followed a manual on how to fix them. I have acquired more and more diagnostic equipment over the years but typically you still often have to use your troubleshooting abilities to fix them.
These days young people especially don't know what you are talking about when you talk about changing the springs in your distributor or adjusting your vacuum advance to get better performance.