I think I am right in thinking that the average lifespan of a car in the UK is 13 years and that the average car is 7 or 8 years old. That 13 year figure will, of course, include insurance write offs so the lifespan of a car that manages to avoid a write off might be a bit higher.
We used to live in Glossop (Simmondley to be precise) and the local pub and Co-op shared a car park. The bottom end of the car park became a dumping ground for old cars - some of which looked in decent condition from the outside. The failure of something like the air con system on a 10 year old car will often see that car in the crusher.
Average lifespan of some cars may be about 13 years, but makes like Toyota and Honda will be considerably more than that, the main problem used to be bodywork corrosion but zinc coated panels, better sealing and underguarding has made that much better, and when was the last time engine or transmission failed on a Jap car ( OK CVT and Hybrid has made transmission much more complicated and a lot more expensive to fix, so cars may be written off due to cost of transmission repairs in the future ). I do not polish the paint on our cars but during the winter and in spring I will wash underneath with garden hose to remove salty mud - which is the main cause of corrosion as every time it gets damp or wet it carries on corroding metal. Large plastic bumpers have stopped the stone chips that used to ruin the front of cars as well, because every stone chip on the metal ( not zinc coated ) was a corrosion point. If you can look after corrosion on a Jap car the sky is the limit for durablity..
Truth probably is that with all the tech in them cars are becoming more reliant on tech that keeps changing rapidly, and may become like phones and Tv's etc. where the tech becomes out of date and either nobody can fix the car or the car becomes unable to meet latest 'standards' ( what they will be we can only guess ). Like 'sorry mate, the tech is only 5G and we can't get the bits any more, you need to upgrade to a car with 10G system.