On average they didn't (oh no, that repair costs more than the "car is worth" as if that's a metric that actually means anything) but it was far easier to keep one running indefinitely. You could take an engine to a small machine shop and get the head and block resurfaced, valves reamed and cylinders lapped. Without any electronics to fail it was just a block of metal that was slowly losing material and a quick hit with a file could even out any imperfections leaving it like new, just with very slightly more displacement.
Modern engines are way more reliable because they have coatings and materials that will last nearly indefinitely in most parts of the engine but they're built on proprietary sensors and electronics that need a steady stream of replacements and secret software to debug.
We could make cars last indefinitely from a supply chain perspective, but commoditizing software and electronics would make them very marginally more expensive. We absolutely can't have that because, drum roll for the 1000th time, 99% of the population doesn't give a flying fuck and wants cheap shit at all costs.
Modern engines are way more reliable because they have coatings and materials that will last nearly indefinitely in most parts of the engine but they're built on proprietary sensors and electronics that need a steady stream of replacements and secret software to debug.
We could make cars last indefinitely from a supply chain perspective, but commoditizing software and electronics would make them very marginally more expensive. We absolutely can't have that because, drum roll for the 1000th time, 99% of the population doesn't give a flying fuck and wants cheap shit at all costs.