Why should you learn new things?
Because you can’t predict the future, and knowing is better than not knowing.
What you learn doesn’t need to be applicable, you don’t have to put it on your CV, it doesn’t need to be measured and quantified, you don’t need to tell anyone.
Learn anything; learn a toy, a gimmick, something too new or too old, something that is popular or something that is niche. It doesn’t matter if it is not supported, not serious or not professional. Learning is an exercise, so the worst that can happen is you get faster at learning the next time.
There are loud voices that cry “new is bad” and call programmers who want to learn “magpie developers” (as magpies like shiny new things), these voices are the dodo developers. A dodo developer will try to convince you that learning a new skill is not a necessary because “we didn’t need it yesterday, so we wont need it tomorrow”. That argument might work for a little bit, but soon the dodo will get caught on the ground when they should have learnt to fly.