I've met precious few devs of any flavor who understand databases. Not just "how do I write SQL," but actually understand what the query optimizer is doing, minor but infuriating differences between DB flavors, and critically, troubleshooting them.

ORMs and cloud DB providers have enabled people to charge ahead without understanding the consequences of their actions, and when latency starts climbing, just scale vertically!

Re: Kubernetes, again, managed services and package providers like Helm have made it easy for anyone to spin up a K8s cluster and even successfully run things on it, without having the underlying ability to fix or maintain it when things go awry.