I guess there is an argument that we wouldn't be able to handle not sleeping, but that would be because we are so used to it, and getting rid of it would force a huge change in the dynamics of our lives.
Yes I suppose we've never experienced a kind of life completely without sleep. I read an interesting article (come to think of it, I think it was on Tumblr haha) about a couple of people who were cooped up in a space without windows/any indication of time and they ended up not sleeping for a very long period of time yet were doings lots of things and being productive. Anyway, the message was 'time doesn't exist, the clock does' or something heavily abstracted. You should definitely look into it, though it may stray away from this topic of sleep but it's an interesting philosophy. Personally, I'm sceptical about it. And I agree with you, having 25 years of time opened up into our lives would be extremely useful, despite logistics such as shops and libraries being closed, can't see in the dark (though I guess you could train yourself) and all that jazz.