Well, there is a lot to unpack here. I am in the same boat (german dev, more than 25 years of coding experience).
First of all, feeling down because you „never ever get it“ to run a business is quite revealing in itself: why do you define your value as a human being by your success to build up and run a business? This thinking in itself, that you are only „valuable“ if you achieve a self-defined goal is questionable.
But since websites like HN project the illusion that everyone who can code can turn this into a successfull business, it is understandable that you may get the impression to miss something or not to be adequate or as clever as everyone else. Yet this is an illusion in my opinion.
Also, you call yourself a hacker and seem to be passionate about technology - this is a totally different skillset than the one needed to run a business, where other priorities are to be set: when you run a business, you‘ll need to focus on your customers and their needs, provide support and sustain or even grow your business.
This is something completely different than being technically proficient. You have to ask yourself if you really want to do that (to take care of nagging customers, to have to deal with stupid shit like business taxes and hires, take on additional responsabilities, or to work on a single technological topic exclusively for years to come and thus have less time to code or learn about new technologies).
It dawned on me quite early that if you like an acitivity (like coding), the encouraged way of society is to build a business around it which turns you effectively into a manager, thus alienating you from the original activity you signed up for.
It seems as if someone is good at something, the „natural way“ is not to accomodate your life to do more of it, but to build a business around it in order to get rich. The goal of the operation however has slipped here, from enjoying an activity to creating money.
But don‘t do more of what you like, but usually become a facilitator to create more money, having to deal with topics you would have never considered in the first place.
This is not what I signed up for (to do more of what I like, namely to code).
„L‘art pour l‘art“ would be my motto. I am not in it for the money (although I need to be able to sustain myself), but for the ride it provides:
„It‘s more fun to compute!“ (https://youtu.be/3odl-KoNZwk)