Nobody said the first example _isn't_ functional. The point is that function composition f(g(x)) is very common in a functional paradigm and many functional languages have added a Pipeline operator as syntactic sugar for this use case.
Nobody explicitly said it wasn't functional, but the original question was "why would you do b (the 'V' shit), instead of a?" ('is this a joke?'), and the response was "well if you care about functional programming you would!" ('is functional programming a joke?'), which is heavily implying that the first example is not functional! (or 'less' functional)
That you don't recognise that is strange to me, and if after my explanation you can't understand that, I don't know what to tell you.
If you can’t understand the difference between pure (no side effects) and functional (applying and composing functions), I don’t know what to tell you.
