The reason to use a tool is to make a task simpler or take a task out of your hands in most cases but the rare edge case. For instance grep makes it easier to go to a file to find a certain line.
If you need to know networking, storage, microservice architecture yourself you don't need any tools.
In k8s you need to know all this, and on top you need to know k8s to achieve the same thing. And then you either need to write k8s plugins or also additionally know all the k8s plugins and wether any of them will actually solve the problem you have.
The reason to use a tool is to make a task simpler or take a task out of your hands in most cases but the rare edge case. For instance grep makes it easier to go to a file to find a certain line.
If you need to know networking, storage, microservice architecture yourself you don't need any tools.
In k8s you need to know all this, and on top you need to know k8s to achieve the same thing. And then you either need to write k8s plugins or also additionally know all the k8s plugins and wether any of them will actually solve the problem you have.