For context, I was introduced to FP (SML in this case) around the same time I learned Java, and I still think for the vast majority of coders, an imperative map is much easier to grok than lenses.
The former only requires understanding how values are manipulated and mutated. You're going to need to understand this anyway to write software, since your machine is mutating values in memory.
Lenses however require complex type-level reasoning, so now you must learn both the value language and the type-level metalanguage at once, and your language also deliberately obscures the machine model. That might be powerful, but it is still an additional mental model to learn.
I mean, just look at the Haskell wiki reference: https://en.wikibooks.org/wiki/Haskell/Lenses_and_functional_...
The route to understanding them goes through Applicative and Traversals, which means have a solid understanding of typeclasses.
You 100% do not need to build a "pile of mathematical abstractions in your head" to use lenses. It's a handful of types and functions. Do you need to build a pile of abstractions in your head to use `std::unordered_map` or getters/setters in C++?