Containerization and orchestration of containers vs learning how to configure HaProxy, how to use Certbot, hmmmm

The questions you pose are legit skills web developers need to have. Nothing you mentioned is obviated by K8s or containerization.

"oh but you can get someone elses pre-configured image" uh huh... sure, you can also install malware. You will also need to one day maintain or configure the software running in them. You may even need to address issues your running software causes. You can't do that without mastering the software you are running!