Gemini is a beautiful idea.
However, it works on the basis of mandatory-prohibition. The prohibition is: "You cannot track and exploit your site visitors". This philosophy is enforced 'remotely', by the creators of the Gemini protocol.
An identical end-result can be achieved in HTML, by choosing not to use hostile markup. However, with HTML the prohibition must be enforced 'locally', by the ethical-philosophical position of the website-designer.
The problem with the Gemini-protocol is that it introduces an attack vector: The Gemini 'browsers' themselves. The most popular one is not audited; has a huge code-base; and has relatively few eyes-on-it.
I'm not saying that Gemini protocol is a honey-trap for those trying to exit the surveillance-internet; but if I was a tech-giant / agency profiting from the surveillance-internet, I would definitely write browsers for the Gemini protocol and backdoor them.
As a former "Don't be evil" company, it would be of great interest to me who was trying to exit my 'web'; how; and why :)
Food for thought...