And how often does that happen with modern day cars compared to old ones? I would argue that older cars, pre electronic wizardry, are easier to repair (assuming spare parts are available) but break down more often. Older cars are also in need of more maintenance.

Modern cars need an inspection every 30k km and hardly ever break down. When they do, they are usually toast so (at least financially). Older cars are financially toast as well, if you cannot do the work yourself so.