Why even have a difference between production and CI in the first place? I see a future where it's Kubernetes all the way down. My CI system is just a differe

Why even have a difference between production and CI in the first place? I see a future where it's Kubernetes all the way down. My CI system is just a different production-like environment. The same job to deploy code to production is used to deploy code to CI. The same deployment that gets a pod running in prod will get a pod running in test under CI. Your prod system handles events from end-users, your CI system handles events from your dev environment and source repo. Everything is consistent and the same. Why should I rely on some bespoke CI system to re-invent everything that my production system already has to do?