Kubernetes isn't necessarily better suited to just YAML -- I usually write Python for that. But if you have a very simple use-case for Kubernetes, YAML is really easy to use, and if you ever find you need the complexity of a real programming language, the Pulumi CLI can convert it for you.
Whether or not you're overengineering in this case depends on scale, IMO. K8s might be overkill. That said, if this is for a side project or something, I say overengineer it! That can be fun, and it's a good learning opportunity.