"I didn't bother to listen, but I think it is wrong so there" is never really a useful discussion position.

The linked page describes a fairly specific set of needs that the claim is effectively true for, though only from the client's point of view.

Anything (hardware or software) in the network stack advertising "zero latency" is a lie. The idea or implementation may have merit, but it is best to avoid opening with a trivial impossibility.

i don't think most people read "zero latency" and think literally 0 ns of latency, because, as you said, it is trivially impossible. If you read any length of documentation you will see how the latency is orders of magnitude less than sending it out directly. That's close enough to zero latency for me.

Yes. Like the random access latency of NVMe SSDs, It isn't zero, but it is practically zero compared to more "traditional" storage tech.

It's nearly as dumb as "serverless"