To your point, which “k8s networking”? My beef with k8s is that it punts on networking altogether and you have to cobble your own with some CNI or another, and depending on which you choose it will significantly impact upstack choices such as load balancing and ingress as well as downstack choices, such as whether you can use Tailscale to connect multiple nodes together (the CNI and load balancer must be compatible with). At least this has been my experience as someone who isn’t a network specialist.

That is not fair, kubernetes uses the same existing technology in a well integrated fashion, including firewalling. That is what Network Policy and Service objects gives you.

Communication between pods running across different computers gets encapsulated in another IP packet. This is pretty standard across the industry.