My experience is limited, but what you're listing above to me sounds an awful lot like some fundamental issues with capitalism and not fundamental issues with technology. I can't speak to the rise and fall of your company, but I can speak with some confidence on your experience at a Tech Giant(tm) and a unicorn startup, having some experience with both and certainly many friends who work at both types of company.
Any Tech Giant office is going to be an absolutely miserable working environment. I had one interview with a larger company and I was struck by how openly bored my interviewers were. Obviously, YMMV and some places may be better than others. But having enough friends, even newly minted college graduates with a "six figs or bust", burn out after 6 months in a development role, it was enough to pretty much convince me to avoid them forever.
Furthermore, the "unicorn" startup is going to be extremely similar to a tech giant but with more desperation. You're joining a team of people who, in all likelihood, have very little attachment to the product and have read a few HN articles about how this is going to be the next big thing. Plus you have the young, fratty egos in play. A lot of these places are going to cover up the fact that it actually sucks to work there with "hey free keg at lunch!! haha don't have more than four ;)"
This might be too hot of a take for HN, but there is, in fact, NO job that you can work at and be valued as a person. You're appreciated for whatever value you bring into the company, but don't fool yourself into thinking that there is anything but a monetary string tying you together. You're not looking at anything wrong, you don't need an attitude shift, the system is broken from the ground up and we're forced to be participants, otherwise we won't make rent.
Find something you don't mind doing; I'd recommend looking at smaller companies with leaders who worked a long time at larger companies. In all likelihood, these companies were founded after the leaders experienced something similar to what you did. But it is your birthright as an American (citizen at least) to be perpetually unfulfilled.
Any Tech Giant office is going to be an absolutely miserable working environment. I had one interview with a larger company and I was struck by how openly bored my interviewers were. Obviously, YMMV and some places may be better than others. But having enough friends, even newly minted college graduates with a "six figs or bust", burn out after 6 months in a development role, it was enough to pretty much convince me to avoid them forever.
Furthermore, the "unicorn" startup is going to be extremely similar to a tech giant but with more desperation. You're joining a team of people who, in all likelihood, have very little attachment to the product and have read a few HN articles about how this is going to be the next big thing. Plus you have the young, fratty egos in play. A lot of these places are going to cover up the fact that it actually sucks to work there with "hey free keg at lunch!! haha don't have more than four ;)"
This might be too hot of a take for HN, but there is, in fact, NO job that you can work at and be valued as a person. You're appreciated for whatever value you bring into the company, but don't fool yourself into thinking that there is anything but a monetary string tying you together. You're not looking at anything wrong, you don't need an attitude shift, the system is broken from the ground up and we're forced to be participants, otherwise we won't make rent.
Find something you don't mind doing; I'd recommend looking at smaller companies with leaders who worked a long time at larger companies. In all likelihood, these companies were founded after the leaders experienced something similar to what you did. But it is your birthright as an American (citizen at least) to be perpetually unfulfilled.