You're arguing against the value of a "big, flat namespace", yet you're also arguing for IPv6, which itself is a big, flat namespace? Do you see the contradiction, perhaps?

Dedicated CIDR for pods is important because it's simple. The symmetry is simple to explain, simple to understand; the same simplicity you'd get from IPv6.

Moreover, it's an abstraction that can be implemented however you want (custom routing on L3, SDN overlay, BGP). Not everone has a native L3 network. If you're on Google Cloud Platform, you get a virtual L3, but with other clouds, the networking is a bit more old hat. So again, simplicity and convenience. As for "overlay junk", the entirety of the Google Cloud itself is virtualized over what is probably the world's most sophisticated SDN overlay, so, well, some people's junk is other people's ragingly successful business, I suppose.

I'm not sure why you categorize the automatic iptables rules that Kubernetes set up as slow or obfuscated. It's only magical in the sense that Kubernetes automatically makes its cluster IPs load-balanced, a convenient system that you are in no way forced to use. If you have a better setup, feel free to use it instead.

We use Kubernetes ingress. It works. It could be better, but it's not "garbage". I really recommend against putting everything in such categorical terms. Everything in your comment is "junk" and "garbage", and the people who designed it (Google!) are morons who don't understand networking, somehow. That kind of arrogance on HN just makes you look foolish.