A well looked after diesel or petrol car should last 20 years, that's not going to happen with electric.
That's a total myth with a modern Diesel/Petrol car. While the car itself would last that long, it's maintaining the many emission systems and complicated electronics that are their downfall. Eventually the costs don't make financial sense once the car has devalued. Good cars are being scrapped due to maintenance costs.
My current two diesels (car and van) spend way to much time at the garage. My 2017 1.6 DCi is around 80k miles and is fully serviced by Renault themselves. yet it's just one thing after another. This year alone it has had a Injector/Glow plugs/MAF/OG sensor. It has also had an full inlet/EGR clean. This week a plastic intercooler pipe has split. So the check engine light is back on FFS! Getting parts is already getting harder on an eight year old car, so i wait.
I got rid of my full main dealer serviced Audi SQ5 last year due to similar. I'm sticking with Audi as i like they way they drive, but it is being replaced with the new SQ6 EV.
EV's are already showing that the battery's are lasting way longer than first thought. Apart from a few "unmanaged" Nissan LEAF batteries, tens years seems to be the minimum they are lasting. Current battery tech is expected to see at least 15-20 years. Future tech, who knows?
Bit pointless anyway, cars as with other things are becoming throwaway items. TV's used to last 20 years. Now you are lucky to see five years. Saying that, TV's are dirt cheap and technology advances by the day. So who wants a TV to last 20 years anyway? (Mind you, some on here would argue Black and White TV's are superior!)
What in the past would have been a cheap ICE car to fix, is no longer the case. Even small faults can quickly run into hundreds of pounds, larger ones into the thousands. A modern car is built to eat itself from day one because of the EGR valve. The entire inlet clogs up no matter how well maintained/serviced. Plastic parts fail way too early.
Don't even start with "welt belt" engines.
Add in DFP/Cats, high pressure injectors, OG sensors. Timing chains are easily £2000+ on their own. (supposed to last 250k+, yet last around 100k)
The last "cheap" car i ran was a 2006 pre DPF Citroen C4. I needed a cheap stop gap while i found another car.
I paid £1500 for it with 107000 on the clock. The owner had already had done a cambelt/service and new brakes/tyres.
I planned on running it for about three months. I ended up keeping it for six years!
It simply ran and ran, without fault other than a new battery after three years. Even that was only due to the electric power steering demanding a perfect charge level. I sold it years ago, and it is still running. My mechanic uses it as a courtesy car. I doubt i would get that with a newer ULEZ ICE car, but sometimes people do get lucky.
The best value cars to buy are probably about 3 years old. (both ICE and EV)
New enough not to have any major faults, yet they have had their biggest depreciation drop.
Used EV mega deals are starting to dry up as people cotton on to the big value they are. The market is changing etc.