Tl;dr: you're technically right, but BEVs aren't sustainable if you need to pay up front for the battery.

A 10-20k battery replacement on a car worth 30-40k used, for an example, is not "regular maintenance" though. And presumably it would come with a new 8 year warranty like the original battery does in every BEV, if you're paying (financing) an OEM battery at the main dealer. Once the vehicle is older and worth less, there will hopefully be cheaper solutions

If BEVs and HEVs can't easily do 20 years of service, we should just stop building them and go back to internal combustion full time. Fuck planned obsolescence.

To be clear I meant there should be government-backed low-interest credit programs for replacing expensive EV parts that would render the car scrap metal when they fail after 8 years and one month. Similar to how you can get student loans with a next-to-nothing interest rate because it's government backed and they mandate a maximum interest rate and payment term. Because otherwise I'm going to trust a 25 year old pollution machine over an 8 year old BEV and that's why there depreciating at a record rate.

You can have an Audi E-Tron for no money at all just a few years after it launched because nobody wants to be left holding the bag. I've owned ICE Audis, Mercs and BMWs with between 300k and 600k on the clock and had no issues that would leave me stranded, except for serpentine belts a couple of times because most of those were bought as poorly maintained vehicles in the first place. I have an easier time trusting a 20 year old car with 500k on it than a 5 year old BEV with 100k or even only 50k on it because I know if I can't sell the 5 year old car before the battery warranty expires, I'm cooked. I've looked at BMW i5, MB EQE, Audi E-Tron, even the Porsche Taycan because they've all nicely depreciated now and I could justify them as a company car (saves me damn near 70% in pretax income compared to buying as a private person), but instead I'm keeping my privately owned 18 year old Diesel A6 because even on a company car I don't want to be hit by a massive battery replacement cost and even if it's a company car, I don't want to buy new because fuck being hit by all that depreciation the first owner gets. But if I could get it at 4% APR for a year or 2, I'd be happy to replace an EV battery to keep it going if the rest of the car is solid and I get a good warranty.