Well we have the latter too. And I think titles = hierarchy has been a thing so long as we've had civilisation. And if there is clarity and alignment on mission and roles, everyone knows where the buck stops.

I don't agree that titles = hierarchy, it simplifies it far too much. Hierarchies are created through behaviours, attitudes & 'the way we are around here'. Each to their own but if we started doing away with titles everywhere, it could be quite a confusing landscape.