I’ve owned a manual for every car I’ve owned for the past twenty-five years and keep an OBDII scanner in all of our vehicles. General curiosity and concern for being broke down at an inopportune time makes it seem like a no-brainer. I have also made most of the repairs on my vehicle thanks to Haynes (and YouTube).
But then I have friends that couldn’t jump start if life depended on it. Seriously. They connected the cables to two random pieces of metal in the engine compartment and fried the whole computer and electrical sub systems. Over $12K in damage.
They don’t get a manual and they don’t want it. Even if you’re well off enough to pay for towing and hire out repairs, it absolutely blows my mind to think people wouldn’t want that security.