Having worked at multiple IoT companies with many millions of connections. This is the way.
People tend to overcomplicate things with K8S. I have never once seen a massively distributed IoT system run without a TON of headache and outages with k8s. Sure, it can be done, but it requires spending 4-8x the amount of of development time and has many more outages due to random things.
It's not just the network, its also the amount of config you have to do to get a deterministic system. For IoT, you dont need as much bursting (for most workloads). Its a bunch of devices that are connected 24/7 with fairly deterministic workloads, that are usually using some type of TCP connection that is not HTTP, and trying to shove it into an HTTP paradigm costs more money and more complexity and is not reliable.