Uniquely human intelligence arose from expanded information capacity

The fundamental point isn't really a new argument and Chomsky pointed out the problems with it decades ago: It doesn't explain why certain cognitive capacities work one way and not another. For example why is language hierarchical and not linear [1]?

[1] The authors (sort of) dispute that language is hierarchical but you can make the same point about many cognitive faculties: Among the theoretically possible manifestations of a given cognitive capacity why is this the specific one that exists and how does it work?