Kubernetes.. almost all the companies are on it or looking at it in one way or another.
If everybody knows kubernetes what is the point to learn it? You can't stand out with this skill if you wouldn't do it professionally. Just to get familiar is enough. I would go with bash, sed, awk.
"You can't stand out with this skill if you wouldn't do it professionally."
But there are an increasing number of opportunities to do it professionally?
And every developer should have bash, sed, awk in their toolbox, anyways, So yes, at least get familiar with those tools and learn to recognize when they are a good fit for a problem you're trying to solve.
But after that it can still be good to learn Kubernetes, too, if you want to work at companies that have large scale back end systems.