Many of the claims are dubious. TCP has "no notion of multiple steams"? What are two sockets, then? What is poll(2)? The onus is on QUIC to explain why it’s better for the application to multiplex the socket than for the kernel to multiplex the device. AFAICT that question is assumed away in a deluge of words.
If the author thinks it’s the "end of TCP sockets", show us the research, the published papers and meticulous detail. Then tell me again why I should eschew the services of TCP and absorb its complexity into my application.
If anything community colleges are more like toll gates. Pay a small fee to use a locally shared resource to then get your job.
The only thing that you need is the ability to configure a target application to choose address to bind to. But any sane application have that configuration knob.
Of course things are much easier with network namespaces, but you can go pretty far with host network (and I'd say it might be easier to understand and manage).
Some people can't help themselves and don't use these tools appropriately.