I hope this post is not too off topic. I thought that it would be nice to see the address of all the small self-hosted instances of Lemmy (1~5 users).
You can definitely have high availibillity without kubernetes, but its easier(For me atleast) with kubernetes.
For container orchestration, which is mostly what k8s provides, then you could use docker swarm or nomad. You could use docker-compose with multiple replicas of the wanted container + a load balancer to divide the load.
In general I don’t think k8s/k3s is needed for hosting lemmy yet, but since I have a setup for k3s, it is easier for me to use it.