That assumes your application can connect to the internet and can be accessed from the internet. There is a vast array of offline-only kubernetes clusters. You

That assumes your application can connect to the internet and can be accessed from the internet. There is a vast array of offline-only kubernetes clusters. You can still of course use self-signed certificates (or setting up your own "CA"), but you'll hit other problems related to runtime certificate reloads and so on. It's still a lot of work to enable SSL for fully offline services.