For example you'd say AWS EBS is part of Kubernetes?
Youre ultimately gonna have to use a storage of some form unless you're just a stateless service/keep the services with state out of k8s. That's why I'd include it, and the fact that you can use multiple storage backend, each with their own challenges and pitfalls makes k8s indeed quiet complex.
But would I say that your entire Linux installation and the cloud it runs on is part of Kubernetes? No.
Maybe with fail over for high availability.
Even that's fine for most deployments that aren't social media sites, aren't developed by multiple teams of devs and don't have any operations people on payroll.
Surprisingly there were hosted services on the internet prior to kubernetes existing. Hell, I even have reason to believe that the internet may possibly predate Docker
Let's be clear on what we're comparing or we can't argue at all. Kubernetes is hard if you have never seen a computer before, I will happily concede that.
I see how you were asking the GP that question now
If you discount issues like that, you can safely say that it's impossible to have any issues with CSI, because it's always going to be with one of it's implementation.
That feels a little disingenuous, but maybe that's just me.