Author here. I appreciate that it can seem silly but it is a very real thing I see happening.

I tried to illustrate with some concrete examples. Like being asked about pods and ingress in interviews, which are kubernetes specific. Experience with docker doesn't help much here, gotta keep up with Kubernetes. You could de-facto fail the interview if the interviewer realizes you didn't work with kubernetes but docker alone.

Companies are super biased toward kubernetes. They're really looking for the unicorn with years of kubernetes experience in production.