I'd say: you should learn as much as you can! That way you can decide for yourself whether or not Kubernetes is for you.
One thing Kubernetes IS helpful with at small scales: portability. If you're fully Kubernetes/Docker, then you won't get locked into (eg) AWS's ecosystem. It's relatively easy to pick up an entire Kubernetes cluster and move it from AWS to DigitalOcean to private hardware.
So even if you're at small scale today but want to design for portability, I'd definitely look into Kubernetes.