Specialization is over-rated. I've done everything in your list except make an ASIC because learning how to do those things was interesting and I prefer when things are done my way.
I started way back in my 20s just figuring out how to write websites. I'm not sure where the camel's back would have broken.
It has, of course, been convenient to be able to "bootstrap" my self-reliance in these and other fields by consuming goods produced by others, but there is no mechanical reason that said goods should be provided by specialists rather than advanced generalists beyond our irrational social need for maximum acceleration.
Jack of all trades, master of none. I also somehow doubt that you've built a car from scratch, including designing the engine, carving it out of a block of metal and so on. And if we're talking modern car, good luck fabbing the integrated circuits in your backyard or whatever. Even your particular generalist fantasy will (and most likely has) hit the hard constraints of specialization real quick.
There is no single human alive that can understand or build a modern computer from top to bottom. And this is true for various bits of human technology, that's how specialized we are as a species.
I started way back in my 20s just figuring out how to write websites. I'm not sure where the camel's back would have broken.
It has, of course, been convenient to be able to "bootstrap" my self-reliance in these and other fields by consuming goods produced by others, but there is no mechanical reason that said goods should be provided by specialists rather than advanced generalists beyond our irrational social need for maximum acceleration.