Kubernetes is a tool for creating computer clusters. Hence the name "Borg" (Kubernetes's grandpa) referring to assimilating heterogeneous hardware into a collective entity. Containers are an implementation detail.
Do you need a computer cluster? If so k8s is pretty great. If you don't care about redundancy and can get all the compute you need out of a single machine, then you may not need a cluster.
Once you're using containers on a bunch of VMs in different geographical regions, then you effectively have hacked together a virtual cluster. You can get by without k8s. You just have to write a lot of glue code to manage VMs, networking, load balancing, etc on the cloud provider you use. The overhead of that is probably larger than just learning Kubernetes in the long run, but it's reasonable to take on that technical debt if you're just trying to move fast and aren't concerned about the long run.