IMO an argument against this is that the benefit though is not in the new tech itself, but different design paradigms it exposes you to and thought patterns you learn.
Even if Rust were to die off tomorrow I’d be happy I invested my time in getting familiar with it as I’ve learned quite a bit about memory management and ways to reason about it.
Paying attention to the design paradigms is truly the interesting aspect. The way you write code in a language isn't fixed or proscribed. You see evolution of languages/frameworks, influence between them, repeats of what one tech has tried and failed (sometimes the new tech tries again and succeeds). The great thing is you can take those learnings back to the language you're using! If you mess around with some Angular or RxJS front-end stuff, you can take that style to the back-end if you want. If you've seen benefit from strong typing on the back-end, you can add TypeScript to a front-end project. Rust and Kotlin have even influenced Java core libraries for the better.
By paying attention to the designs it's easier to figure out what's marketing-driven hype as well. For example, do I really need to jump onto the next serverless platform, or are they just repackaging and upselling AWS Compute resources? Can I accomplish the same thing as the latest edge computing platform by using service workers and a free CDN? Is Firebase Hosting basically a second interface for GCP Cloud Run?
Even if Rust were to die off tomorrow I’d be happy I invested my time in getting familiar with it as I’ve learned quite a bit about memory management and ways to reason about it.