I love these numerical thought experiments. The only reason I haven't done my own version is 'cos I'm saving it as something to look forwards to!
The future doez indeed look bright... we really don't need that many people in the grand scheme of things to soak up all that future supply of steem.
Cheers!
I am not good with numbers so I try to keep them simple which is fine to get s view of the possibility. One day, I will hire Asher to teach me how to do it properly. :)
Not many people needed but many might arrive. This is why there is the need for so many Blockchains too. Everyone wants Facebook, but the beauty of decentralization is, Facebook is not the goal for the win.