The reality is that engineers with a strong foundation in the fundamentals can pretty much pick up any new technology. The details are different, but the underlying principles of software engineering, algorithms, data structure, distributed systems, etc. are the same.
I guarantee you that a talented kernel hacker, with a few weeks of reading the docs and writing some toy examples, would be just as productive in React as the front-end developer with years of experience.
I work in a pretty niche industry, where hiring people with specific experience in the tech stack is rare or impossible. So, I see this up-close and personal all the time. Fluid intelligence, an understanding of computer science fundamentals, and a demonstrated history of delivering results trumps specialized experience with the specific technology. Every. Single. Time.
Keeping this in mind relieves some of the anxiety of keeping on the treadmill. You might feel like if you don't start getting experience with Kubernetes or Typescript or Airflow that you'll be left behind. The reality is that if you're smart, then if/when you need Kubernetes/Typescript/Airflow, you'll be able to pick it up in a week or two.
I think some of the industry-wide problems with this come down to the fact that HR is too involved in the recruiting process. The typical job listing gets written by someone who's never written a line of code in their life. They just walk down to engineering, talk to the manager, hear something like "we're using Kotlin", then decide to add "5 years of Kotlin experience required".