Agreed, apologies if I misunderstood your point. It was the “are you useful to me?” comment I got hung up on. As it appears to suggest that people would only be make inter-personal decisions if other people are ‘useful’ to them. Which is only true for individuals with sociopathic tendencies i believe. It is also the same argument that Harari uses when framing his world view.

I will also point out, two things can both be true, simultaneously:
1)- Bitcoin leverages some of the elements of selfish human behaviour to provide security and manage incentives
2)- Not all actions humans perform are motivated by selfishness 

These are not mutually exclusive.