Google "chipping" and "remapping." The tools are still there (just different) and people are still using them.
There have always been wankers driving cars; there have always been people willing to fix their own cars.
Unfortunately, there doesn't seem to be a whole lot of substantive data on who does what and who
can do what in the respective eras, and what there is (most anecdotal) doesn't seem esepcially reliable--like the guy on the internets who claims he can stack a cord of wood in half an hour!
That's nothing. The 1975 Pontiac Sunbird required lifting the ENGINE out to change the spark plugs. Cars have gotten considerably easier to maintain since then; "design for maintenance" has become a thing.
Hmm. To me, it's the newer stuff that always seems to be more convoluted in design. With my Westfalia, you can access pretty much everything with a very basic toolkit--you can even improvise if you can't locate the particular optimal tool. And seriously, I have to go through an unbelievable number of steps just to access a bulb in the headlamp on the Subaru; whereas on the VW, I can replace it in seconds (and unlike the guy who can move tons of wood in minutes, I'm not exaggerating)
We have an LG washer/dryer-in-one combo-thing on which I had to replace the drain pump the other day. I had to dismantle the entire thing: remove the top, disconnect the control board, remove various compartments for soap and drains and suchlike on front, remove
the door!, unfasten the band from the bellows just so I could disconnect the door locking mechanism, and so forth... All that to access a drain pump, which wasn't even broken, but rather just clogged (dogs!). Either way, I still had to dismantle everything to remove the obstructing dog hair.
Like what? I regularly changed engine oil, replaced filters, did inspections (CV boots, coolant hoses etc) from my first car (1973 Datsun) to my latest gas car (2005 Prius.) I now have two EV's that require zero maintenance, so haven't done that in a while.
What about the electrical systems? This is less of a maintenance issue, and rather has more to do with mishaps and such, but with newer vehicles, a "fender bended"--or being side-swiped in a parking lot--can result in a whole lot more damage than simply a bent fender. With an older vehicle, one can often make a few temporary makeshift mends, and then drive away and make repairs at their own convenience. With a newer vehicle, "makeshift mends" are less likely to cut it, compelling one to require payed service, i.e. towing, whatever, on the spot.
I don't wish to say that the more exhaustive and comprehensive electronics in newer vehicles are universally a "bad thing," obviously, but they do sometimes present obstacles which had previously never been conceived. There's a weird little hypothetical scenario I always return to regarding automatic windows and doorlocks: a person drives through a flooded roadway (which they shouldn't be doing in the first place, but, you know...), electronics fail and because they're in drive mode, the door is locked--and they can't unlock it manually; the windows are up, and they can't manually roll them down--so what do they do? Break the window to get out of the car?