Gemini also transmits a mimetype that’s text-based (text/gemini) but it runs on port 1965 — as opposed to the usual 443 (HTTPS) or 80 (HTTP) that Web browsers usually connect to by default. Gemini therefore needs customized “browsers” that will read the protocol and parse the data that’s received from a Gemini server, however there are Web Proxies that do this as well [0].
In that sense, it’s an alternative to the Web inasmuch as it’s an alternative to HTTP; but (importantly) without any maturity, performance, or scalability whatsoever.
Now to be fair, Gemini doesn't claim to replace HTTP in any way; being a niche, small-web technology.
But in my opinion it's pretty pointless since it uses a strict subset of the HTTP spec which makes it feature-delimited by design.
Using HTML sans CSS/JS will give you a similar yet better experience.