A major difference is that our relationship to risk has changed. For example, working on some parts of a Tesla or some parts of a hybrid would mean working with high-voltage equipment. Although I know some of the principles, I am hesitant to be my own electrician. I'm very cautious just doing a jump start.
Of course, this has always been the case, people just accepted (or didn't understand) the risks. The capacitors in an old TV could pack quite a charge. Working on a roof has its risks. Early chemistry kits let kids blow stuff up. Apparently it was accepted more, before.
There's a weird relationship between electricity and self-confidence that I've never quite understood; suspect it's similar to the phenomena that enables math to be the only general academic subject in which it is socially acceptable to suck at, and/or related to a lack of "correction window" when tinkering with forces that propagate at the speed of light.
That being said, I'd posit that having a set of technical manuals at your disposal would dramatically change this perception to the detriment of certain lucrative service markets. Everything breaks; the real question is who has the capacity to administer repairs, and at what cost?
It's really easy to kill yourself if you go messing around in your house wiring. It's possible to be safe, but it's not on the same plane as messing with an unplugged washing machine or TV.
Barring fires it isn't that hard. Just turn off the circuit breakers for absolutely everything in the area and test the voltages just in case there is any capicitance before touching any wires. I am a complete neophyte with wiring but that part is simple.
I took OP's comment to mean that tinkering is largely unnecessary now. Previously with both cars and computers you needed to know how to tinker because things didn't work perfectly so often. In the 80s both your computer and your car would need servicing/troubleshooting more often than today. I never tinker with my car or laptop now simply because I never have the need.
For some reason I still need to repair my computers, dishwashers, cars, etc. see https://jeena.net/posts/114 or https://jeena.net/thinkpad-t410-speakers-fix and it's still possible if you have the luck to have bought something which is possible to be repaired.
There are only two things that genuinely preclude owners from servicing their own vehicles (Tesla or otherwise): a lack of will, and vehicle manufacturers refusing to sell technical manuals[1] to anyone other than authorized service shops.
Sure technology has appreciably advanced in 30 years, but the fact that technical details and know-how are scarce commodities in the age of information is not a generational coincidence.
[1] https://www.helminc.com