older cars were more repairable. reliability is harder to make a blanket statement about.
the most important difference IMO is that older cars are now dangerously unsafe by modern standards, by orders of magnitude. crumple zones, multiple airbags, pedestrian scoops, and now driver-assists like emergency braking.
Cars are a bit of an anomalous category here. Driving is a pretty dangerous activity, so it's pretty sensible to give up some reliability & repair-ability in order for a safer road-coffin.
This is much less true for something like a fridge/thermostat/tractor.
the most important difference IMO is that older cars are now dangerously unsafe by modern standards, by orders of magnitude. crumple zones, multiple airbags, pedestrian scoops, and now driver-assists like emergency braking.