[thomseddon]

Homo Deus (the sequel as mentioned) answers the question of why he has formed his particular view of the future.

In essence, yes economic incentive is the basis for much of today's human corporation, but with growing AI/robotics, the same economic incentive will make much current human input unnecessary.

Then, for example, would counties see so many humans as a big cost? How do they solve that if they no longer need them to work?

Scary stuff.

[vages]

You could have asked the same question in 1700: What will the state do with its inhabitants when they no longer work the fields or make wool? The answer is “something else”. The economy adapts, and unimaginable professions and social structures appear. I would be amazed if anyone in 1700 thought that programmer could be a profession.

And maybe we don't need as many as 6 billion people on earth, maybe one billion will do (the slow population growth in industrialized countries indicates that depopulation is possible). But the need for them won't disappear overnight; we are nowhere near artificial general intelligence, no matter what Ray Kurzweil tells you.

[bilbo0s]

>the slow population growth in industrialized countries indicates that depopulation is possible

Slow population growth, does not lead to depopulation.

(Not that we would need depopulation anyway. More just a point that slow growth, is still growth.

[Engineering-MD]

Your point is, of course correct: slow growth is growth. However, it worth clarifying that population growth in much of Europe is driven by immigration rather than natural growth, and therefore does demonstrate population decline which is offset by other regions population growth.