You don't have to run kubernetes for containers, but even then, only 4 of our engineers know and operate kubernetes. It allows us to enforce routing, authn, and authz standards everywhere (and test locally). Application engineers only need a simple command to run their stack and some code templates to build and test applications. Not much knowledge is typically needed on their part. Is it always perfect? No, but it's a lot simpler then wiring up a bunch of vendor specific offerings.