We use Kubernetes for our cloud database platform, which we are extending to new environments. It's been quite successful. We were able to port from AWS to GCP

We use Kubernetes for our cloud database platform, which we are extending to new environments. It's been quite successful. We were able to port from AWS to GCP in a matter of weeks. We don't try to share tenants within a single Kubernetes cluster. With that experience in mind, the storage section of the article is a hand-wave. Kubernetes is a major platform for high performance databases themselves. Saying that Kubernetes developers should "use databases" is not a very plausible answer in this case. Object storage is not a panacea either. It does not exist equally in all locations and building caches to make it work efficiently in low-latency apps is a non-trivial exercise. (Like years of implementation work by PhDs if you want something good.) Locally attached NVMe SSD is still the winner for a lot of applications. It needs to be first class in Kubernetes and it needs to be easy to allocate pods that offer it. Applications can deal with resilience through app-level replication. Databases have been doing it for years.