Yes, they are inexpensive to manufacture, doesn't mean they're assumed to be standard in an affordable car.
While heated seats might be cheaper to manufacture, I'll bet that hasn't proportionately affected the price they're sold to individuals at.
You're right, low cost to manufacture doesn't mean it's cheap as an OEM part. On the other hand, non-oem is not expensive, nor is it difficult to install.
Okay, let me back up a sec: I put my electrical engineering degree to good use by reading the schematics. They're made for mechE, not EE, but they're readable. There are only a couple things in my car (2000 model) I would be afraid to touch from an electrical standpoint. Even on newer cars, the only things I wouldn't fuck with are the infotainment/gps system since it tends to tie into the car, and the engine control.
"But what about drive-by-wire and brake-by-wire?" Admittedly, I think brake by wire is a shitty idea, but that doesn't mean it's difficult to mess with - generally, you just have a wire with a bunch of connections, and you can unplug and replug that wire in. Just like the mechanical components that hold your struts, or your transmission, or your engine - scary consequences if you mess up, but not actually difficult to understand.
So I mean, some home mechanics can rebuild their carburetor or their engine or their transmission. I don't know how yet. On the other hand, I'll learn and figure out and do anything necessary to wiring and electronic components that are hooked up in a straightforward way, because to me that's all straightforward. With that said, it doesn't mean I know how to debug the issues, because
that often needs fancy hardware specialized to shops or often only dealers.
Maybe if you are buying a new, mid-range vehicle for $24,000+, but I would argue that that is not comparable to what (used to be?) considered middle-class. Maybe I am off though.
But to the last part: isn't it? A $24k car, times two, every ten or fifteen years. Fifteen years ago a $24k car was not a basic model; today... well, that's around a Camry MSRP. Not a particularly fancy car.
Whether "middle class" should buy on average a new $24k car every 5-8 years per nuclear family is entirely another question. Probably not. They would probably do better with buying a $7k camry from a previous generation. But it's well within their means: median household income is $50k a year; taxes on a family of four aren't terribly high; that's about 5-10% of post-tax income per year over the vehicle's life to finance it and maintain it. Again, should people be spending 5-10% on their car? Maybe not, but it's easy to see how they can find the money to do it, and so it moves up to being a "middle class" thing.
I assure you, my memory is good enough to remember fifteen years ago, and this hasn't changed (except the prices have gone up, inflation happens.) I don't know a lot of people earning the median wage anymore (everyone is too young to have families and buy family cars, and I don't know what their parents are doing anymore, and also bay area salaries mean people often buy luxury cars instead.)
The features, by the way, of an entry-level car over those of one from fifteen years ago are much improved. The updated version of my 2000-model car is safer, gets about 50% more mpg, and gets more power from the engine. I'm sure it also pairs with your phone over bluetooth or whatever other stupid shit people want.
Also, I do legitimately hate power windows. Jesus Christ, just pull on your big girl panties and use a little muscle.
My muscles aren't long enough to roll down the passenger window, let alone the ones in the back, when I'm driving. Being able to control windows is excellent. I would say for me it's a requirement: I love to drive with the windows open; I love to drive long distances that see temperature swings of around 40 degrees F; and I would prefer not to sweat my balls off (90 or 95+) nor freeze them (55-) so it's quite nice not to have to pull over to adjust my windows, you know?
And what the fuck is with electronic key fobs? How fucking difficult is remembering what your car looks like and turning a key? I could see an argument for keyless entry being more secure, but how is the bee-boop button thingy an improvement? It's like the world is being built for children. But, um, that's probably exactly the grousing, luddite attitude you had a problem with.
Beep-boop as in the honking cars make? That's obnoxious. My car makes the sound of locks closing or opening, which is appropriate because locks close or open. As far as security goes... let's just say that most high-tech methods of security are significantly worse than a key. The benefit is convenience, really. Also the ability to light up a large area, then turn the lights off once I don't need them. Also not needing to de-ice my locks. The cost is approximately nothing. It costs $200+ to install an after-market remote fob but it costs approximately zero to design one into the car, which is why it's standard on all but the most barebones of cars. But here's the best part: You usually get a set of spare keys with your car without the fob, so you don't have to use it, ever, if you don't want to. You won't even know the feature is there. Just like heated seats, OEM parts may be a little expensive but the actual addition to the BOM for which you have to pay is nearly zero.
I hate power windows too. I've had more ridiculous intermittent faults with power windows... Mechanical windows are pretty reliable. Power, not so much...
Won't argue with reliability. The regulator can slip and the motor can burn out. My parents have one window in a car that sometimes refuses to go up or down, other times works fine. They were quoted a fairly large amount to repair it. I can do it in an hour with $30 in aftermarket parts. Still, it's annoying. With that said, don't pretend you've never seen manual windows jam or the handle fall off. Oh god, how many fallen-off handles I've seen... for pure reliability, mechanical might be better, but factor in improvements over the last however many years and how much those handles tend to stick out and how roughly people treat cars, and I wouldn't be surprised if current power windows break less often than the damn handle fell off.