None of those things are N years in the future. That's a bad meme. We have had fusion that works, flying cars that work, and airships that work for 50ish years.

None of those things are N years in the future. That's a bad meme. We have had fusion that works, flying cars that work, and airships that work for 50ish years. A thermonuclear bomb set off in a giant underground tank of water would make a lot of power and we would have no trouble controlling and harnessing that. We just don't want to do it that way. We already have tons of trouble getting people to approve building a controlled nuclear melting pot anywhere near them, no one would ever agree to let you detonate bombs under their feet. That doesn't mean the tech doesn't work. It means we don't want to use it. And flying cars have existed since the term was invented. They're called airplanes. You can get a four seat one to fly yourself for about 40k. They are a bit harder to "drive" than regular cars and we don't make as many places to park them so most people don't want one. Plus gas prices already limit how much people drive, try burning 10 gallons/hr. Airships work too, they just occupy a niche that we do not have a need for other than entertainment value. Cargo ships get lots of stuff across water cheaper, trucks get stuff across land cheaper, and cargo planes get more stuff through the air faster.