It's also just a parrot trick. There's no reason behind why it is 30 years away or even why 30 instead of 15 instead of 20. It is just a line. These numbers are meaningless but touted as a way to add validity to the argument without providing actual evidence for why fusion is such a tough nut to crack. We should dispose of hype, but let's do it from a place of understanding. I hope we're a bit smarter than parrots.