I'd only add that it's another way to manufacture hope for people who have been left behind by how unbelievable most religions are.

I've been trying for years (and will continue trying) to switch my parents hope for an afterlife with a hope that cryo will work. There is definitely no afterlife, but cryo might eventually work. That's how I see most of these "living forever" positions. It's just a more intellectual hope to have, where you at least break reality into possible and impossible before choosing something to believe.