If the price of a stock or house or investment have been rising for two years, it's risen in cost to get into, and you might never see the gains people have seen in the past; I doubt you'll ever get a bitcoin for a dollar again!
But if job adverts for a new tech have been rising for two years, it doesn't cost any more to learn than on the day it was released. Maybe less, in fact, as there will be more tutorials and more experts to learn from.
Kubernetes is pretty lean. It does require a significant mental load to get up and running, but that's mostly due to how it forces developers to venture into the old and largely unfamiliar sysadmin territory, where you need to pay attention to more stuff other than the compiler finishing a build job.