Per the K3s web site and their docs, they don’t call out that it’s good for bare metal production. That tells me it’s not built for heavy workloads, and is instead for dev environments and edge compute.
The default k3s configuration is not scalable which is especially bad for etcd.
Etcd can be replaced with postgres which solves majority of issues, but does require self-management. I've seen k3s clusters with 94 nodes chug away just fine in the default configuration thought.
