On the last paragraph in the article (criticism of the lack of extensibility of the protocol), Gemini itself is a protocol largely designed to improve on the modern shortcomings of the gopher protocol, so if ever Gemini were to fall short of the demands of the type of people that use protocols like this, the solution is right under your nose: make a new protocol.

I'm a big fan of Gemini. I think the philosophy around light document delivery over the internet is very important. And the lack of extensibility is a core part of that, Gemini cannot be everything to everyone, by design. And no protocol should, I personally find the idea that http is used to deliver news articles and web apps to be a bit ridiculous, the protocol was extended well beyond what it was intended, and I can find no reason for this other than that people don't like typing different things on the left side of the "://", if they ever even type that part at all. Imagine an internet where people routinely use different protocols (and know about it), how much cleaner the experience would be.