I completely agree, and it's not just the battery but the systems technology that go along with it, the cooling system, generator, computer interface, etc.
Maybe it’s the crowd of people I associate with, but pretty much everyone I know, keep their cars until the cost of maintenance is equal to, or greater than the anticipated car payment.
I drove my 97 Lexus for 15 yrs and 312,000. Best car I’v ever owned. Never touched the engine or tranmission - just typical wear items (brakes, battery, tires, belts and plugs). My ‘05 Acura TL still has plenty of life left in it, and at 80,000 miles; will be around for the forseeable future. My ‘03 Tacoma has 120,000 miles and is going strong. I see myself replacing the seats in the Tacoma ($6-800), but the engine and transmission are fine. I expect at least another 100,000 before anything major happens.
I don’t think people are getting rid of cars like they used to. Cars are lasting longer - 150,000 miles is becoming the norm. Some people may change cars every 8 yrs, but those cars are staying on the road a lot longer than ever before.
8 yrs, IMHO, is not acceptable anymore. Now, I think 12+ yrs is the expected lifetime of many cars. Perhaps I’m full of poo; but this is my observation. Yours, may of course, differ.