Kubernetes (abbreviated K8) is an infrastructure topic. One also speaks of "infrastructure as code" (short IaC). With the help of K8 you can define the infrastructure in which the software we have programmed should then be embedded.
We are a software engineering company and focus on the development of applications. Where the software then runs is often of secondary importance to us (or the customer has explicit requests). The fewer obstacles the underlying infrastructure puts in our way, the better. That's why we rely on external partners (e.g. Google, AWS or Nine Internet Solutions) to operate Kubernetes, as we do for other hosting issues.
To be able to work with K8, you also need to know Docker. If you find K8 too complicated, you might be satisfied with Dokku.