> Fusion is bullshit.
Especially because the Tritium fuel problem is not solved, and nobody has the faintest idea how to solve it. The materials needed to breed Tritium in something different from the Sun (or thermonuclear weapons) just do not exist for now.
Yes, any global energy system will be extremely expensive. Trillions of dollars worth of expensive. That it is a lot of work is not a showstopper.
I don't see nuclear being part of that solution, though. Why waste money on something that is demonstrably inferior? It had its chance. We don't need to invest in losers.
Fusion is not an endgame. Fusion is bullshit. It's Rube Goldberg on stilts. From an engineering point of view, it's pretty much the opposite of attractive. Keep It Simple, Stupid is not just a slogan.
DT fusion makes no sense in space. The energy comes out as neutrons, which get turned to heat. You can make heat with fission in space much more easily, and with much less reactor mass, than you can with fusion. The notion that fusion is somehow good for space comes from science fiction more than anything. It's a trope, not a good idea.