Tech Republic has an article entitled Top priorities for professional developers: Why devs are always looking to learn new programming languages. It's not until the bottom of the article that we get to any mention of programming languages versus programming skills in general. General skills are about things other than languages: Kubernetes and AWS are configuration skills, not languages. React is a skill and not a programming language. Using an IDE effectively is a skill and not a language.
"Opportunities for professional growth" and "Developing my skills as an engineer" are what are listed as the "top priorities," which includes but doesn't specify programming languages.
Nonetheless, I think that there's an important kernel of truth to the idea that it's languages that developers want to learn, because programming languages are the only things that teach you how to think better.
Underlying React are two concepts. The first is the zipper. Zippers are fascinating and tie in, ultimately, to type systems, advanced data structures, and "regular languages," one of my areas of expertise. Zippers are a damn complex data structure best explored in one of two languages: Scheme, or Haskell. You can't understand zippers until you've mastered one of those two languages, and understanding both allows you to understand both the mechanistic (Turing-machine) and theoretic (Curry-mathematic) interpretation and implementation of zippers. The other is the continuation, which is the fundamental data structure that allows programs to handle decision making. All decision making in a program, every
if statement, every exception, every loop, is in some sense an implementation of a continuation. Scheme, again, is the fundamental programming language necessary to understand continuations. React uses both zippers and continuations, but as a developer you'd never need to know or learn about them.
But if you read enough Haskell and enough Scheme, you will. And that's why, although programmers have to want to learn how to configure cloud deployments and networking and so forth, that's just plumbing. Learning a new programming language gives your brain the tools necessary to do the exciting new stuff.
I don't know a single Haskell developer who doesn't believe the weak version of the Sapir-Whorf Hypothesis.