It is at a heavy cost. A car receives support anywhere close to as we think of it in the software world for only a few years or a certain mileage limit. During that time, if there are problems, they fix it. However after that, it is your dollar. Also it is only repairs, no updates.
I have a 1996 car and the dealer will still work on it, you can get parts, but the charge quite a bit for both the parts and labour. There are no updates to it, no improvements. Subsequent models got a more powerful, turbocharged, engine but I don't get to have that retrofitted unless I want to spend serious money (and the dealer won't do it, someone else would have to).
People need to STFU about MS support as it is actually very good. Their OS support is 10 years from date of initial release. So when an OS comes out you are guaranteed security fixes for at least 10 years from the release date. Sometimes they'll extend that, but you get at least 10 years. That is split in to 5 years of general support, meaning it tends to get service packs and often new features, and 5 years of extended support meaning it tends to get only security updates.
That's not a bad lifecycle. Even the LTS very of Ubutnu is only 5 years, OS-X is two version behind the current, which translates to like 3-4 years. At 10 years of support, with no subscription or anything, MS is not bad.
It isn't like this XP thing is sneaking up on people, it has been known for a long time, some people are just choosing not to deal with it.
Also, realistically, if you get the most current Windows on your computer when you buy it, it'll last for the life of the computer. Even if it is a couple years in to support, the computer is likely to be very old and slow, and probably breaking down, by the time it goes out. For example if you bought a system with Windows 8 on it today, it would go out of support in January of 2023. My guess is that 9.5 years from now, whatever you bought will be showing its age pretty badly, if it even still runs, and be due for a replacement. Heck even a system with 7 goes out of support in January of 2020. So over 6 years until you'd need to upgrade, and again, might be new system time at that point.