Comment by ACCount37
Repair shops are a necessity.
Not everyone can learn even the basics of car maintenance. There are a lot of drivers on the roads today who wouldn't be able to do even something as simple as top up the oil or change the tires. And actual repairs, even on older simpler cars, even with an exhaustive technical manual and modern learning aids like video tutorials or AR overlays? Fat fucking chance.
There are ways around that. You can keep the cars simple to repair and also expensive and unavailable, so that only the people with tech know-how and/or willingness to learn it get them. Make cars as tools for professionals and tech enthusiasts, like PCs were in the 80s or construction equipment is now. Or you can make the cars cheap and disposable enough that if one fails, you can just send it to a scrapyard and get a new one.
I don't like either of those workarounds, so repair shops are the least bad option.
I visited Rumania around the year 2000. I remember being surprised by the sight of a whole bunch of similar Dacias at the end of a (muddy) street, in various state of disrepair. The person we visited explained that people were repairing their cars by taking parts from other cars, as there were no spares, or they were very expensive (the average Rumanian was pretty poor at that time). And since nearly everyone drove a Dacia 1300 (tried to guess the model; they looked like a Renault 12), there were plenty of donor cars around, and people learned how to fix their cars from their neighbours.
That can't last forever, of course, but it shows there are other ways.