I don't think the first example is less pure than the second, what makes you think it is?
The pipe operator is just one part of functional programming, composing and applying functions
`f(g(x))` is still functional, and I would argue it exactly what is happening in the first example.
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.
It's not a problem, don't worry about it you will get there. Enjoy your day!