The Littlest JupyterHub is an extremely capable hub distribution that I’d recommend for situations where you expect, on average, under 100 active users. Why not Kubernetes? The primary reason to use Zero to JupyterHub on k8s over TLJH in cases with smaller number of users would be to reduce costs - Kubernetes can spin down nodes when not in use. However, you’ll always have at least one node running - for the hub / proxy pods.
