Supposedly the electronics were too complicated for a shop to diagnose and fix the car on the spot, but I imagine the real problem is that diagnosing non-obvious problems is tough for anyone to do on the spot because all mainline service centers for the big manufacturers are weeks behind and can't just squeeze in the 4 man hours it might take to tear down and diagnose random problems. Older cars and systems were cheaper and easier to diagnose, but they also probably broke down once a year or more, while I had no issues with a 80k miles-in-2-years 2018 Honda Accord and still going strong with a 60k mile no-maintenance 2020 Tesla Model 3 SR+.