They would also do maintenance. Cars used to require an absolutely huge amount of regular maintenance and having someone local to do it was a net win.
To a degree ICEs still do. Check the recommended service intervals in the user manual on a modern car. You basically need to visit the shop at least every year or sometimes every 6 months.
Obviously the sky won't fall if you don't do it as often as they recommend and the car will run just fine, but then you're voiding your warranty in case something breaks.
Old cars needed a ton of work frequently.
Check out this 1950s car owners manual: https://chevy.oldcarmanualproject.com/chevyowner/50om22.htm