So what? You’re not never going to find one thing to learn for all time. Things change. The point is to get started and then follow the industry.

Who cares if what I do today is obsolete in a few years, by then I’ll be doing something different.

Don't learn the language. Learn the fundamentals. The fundamentals remain constant.

Tough to get hired on fundamentals these days.

A lot of jobs out there only test you on fundamentals. Hackerrank questions allow you to pick whatever language you like.

In most jobs you will not get a foot in the door if all you claim to know is fundamentals. If you do not know the languages or frameworks they work in the interview is over as they are not going to spend the time training you. They want you to get in and be effective as soon as possible, not pay for your on the job training.

Personally I have found that this is relevant only for front end work. For the backend you just need rudimentary knowledge of a framework/language to get your foot in the door, then the actual testing is language agnostic.

Makes sense. Us front end guys are fairly expendable.

Don't pigeonhole yourself into the frontend. Be language agnostic. Mastering the fundamentals allows you to transition across the stack.

That usually happens after the CV screening, no?

I'm willing to bet that Node/JS devs actually have an easier time staying current, since their workplace actually has a need to change technologies, so they're getting paid to keep rewriting their web app in $the_latest_framework, which they can then put on their resume.

Sort of. The difference I guess is that you can still put javascript on your resume and it'll do something for you.