Why isn’t a toaster a general purpose computer? There are toasters with wifi, touchscreens and other functionality.
As for your car question - why not? No one would buy such a crippled device. The problem would resolve itself.
If a car manufacturer sold a car without a steering wheel that self drove, perhaps people would buy the car in spite of the limitations. What they shouldn’t do, is buy a car advertised without a steering wheel and then complain that it doesn’t have one.
Come on, to assert that a "smart toaster" is not categorically different than a laptop or a smartphone is a bad faith argument.
I think market forces don't work well in cases where you have a lot of vertical integration, and increasing consolidation.
The "just don't buy it" argument only works in a competitive market with lots of offerings. What we have in the world of computers is more of a lesser-of-a-few-evils choice in virtually every technology choice.
