> Long verbose names don't cost anything

They absolutely do have a cost. The question is whether the benefit they bring in implicit documentation is worth their cost.

> Even beyond the DX of readable names, it also acts like a type-checker. By reading the code, you can verify at least the semantics make sense.

I would strongly prefer that the actual type system do this job instead. As a toy example, if a function is only meant to operate on "lengths" (i.e., non-negative scalar values) then that should be modeled in the types of its arguments, not in its name.