I think it depends on where you want to work. If you check out the YC job boards, they want TypeScript, Go, and GraphQL.

I've found in general the places that use Java don't look for a Java developer. Its like they just assume you can pick it up. You might see things like knowledge of OOP, SQL, etc. on the job listing. For example, lots of large companies like Google, Microsoft, Amazon, Twitter, Netflix, etc. have a ton of Java, but their job descriptions don't really mention it.

On the other hand, if a place needs Typescript, or GO, they'll mention it.

I think job descriptions are just marketing materials for developers at a lot of places. Advertising your COBOL just gets you people that want to make more COBOL.

Every job I take, whatever the oldest crappiest technology mentioned in the footnotes is, ends up being 90% of my job.

Sure. If I want to only work with the hot tech then yes, my choices are limited to companies using hot tech. But the reality is that the vast majority of development jobs are using the old standbys.