Humans can't write bug-free code, it's beyond us.

With space, they literally write more multiple lines of specs for each line of code, test the crap out of it, build a ton of redundancy, and have many people go over every line with a fine toothed comb. It's a very long and painful process, and they still have bugs

The defense industry and aviation isn't that amazing - they just have insane budgets, iterate for a long time, and (usually) have someone there ready to take control. It takes them years to perfect anything too

I do agree software is sucking way too much these days though. I think it comes down to a) most projects don't get the years of maturation you need to make something rock solid b) developers have to frequently change jobs because they're rarely given raises for some reason... And one dev isn't as good as another and c) you don't make money by making good software. You make money by making it fast, and finding a way to monetize it heavily

There's also the fact that modern software is built with endless layers of open source libraries, and there's basically no money there. They get abandoned or replaced all the time, and changing/upgrading them is an ongoing process.

I also have a theory that COVID has made the whole situation much worse, and the economics of it have recently gotten much worse