So just do that then in the cases where you think it improves clarity? It's not like you can't assign names in the functional style if you need to.
I have quite literally zero times in my ~25 year career had to deal with some sort of completely inscrutable chain of functional calls on iterators. Zero. I am entirely convinced that the people arguing against this style have never actually worked in a project where people used this style. It's okay! The first time I saw these things I, too, was terribly confused and skeptical.
That said, you didn't address my comment at all. It might be easier, but that doesn't mean it is easy to figure out what that long chain is really done - all too often the algorithm names don't tell you what you are really trying to accomplish in my experience.
A strength of functional idioms is that they expose the structure of the code in a way that a name - even a well chosen name - can only hope to achieve. Often, succinctly and comprehensively. At that point you stop caring so much about variable names. They’re still there but you need them less