Of course you can just disable javascript in your HTTP browser. But as the author states, it's easier to write a completely new client than to disable all the bloat in e.g. firefox.
Screen readers handle Gemini just fine - one of the clients I've tried outputs text and buttons in a GTK window, another literally just outputs text into a terminal and takes command line input, if a screenreader couldn't handle that I'd be horrified. The format is paragraph-based, there's very little styling, no guessing at what the main content on a page is.
I think screen readers can read text pretty well, also, since you've declared that to be a goal for some reason.
It's a waste of time compared to just making something new. That doesn't mean that normal browsers couldn't also get gopher support for those not interested in a lightweight browser.
You cannot do anything lightweight with a browser supporting, and itself being written in, web technologies.
Fragmentation is intentional. Although, nothing stops a web browser from also gaining gemini/gopher support. Just won't be "minimal".
Introducing new technology doesn't change the technology everyone else is using if it doesn’t provide a reason for them to switch. Gemini seems to appeal very much to the issues of a very narrow group of users and, I suspect, an even smaller proportion of content creators. I don't see how it has any effect on the technology everyone else is using.
You could try the same thing with a community dedicated to minimal HTML--heck, you could say that's what HN itself is, almost--but it would have no effective border. You'd keep falling back into the bad old web. This makes the border explicit, instead.
Creating an entirely parallel stack is the only way to obtain minimalism at this point.
Appealing to those liking web technologies would be counter productive, as they're part of the problem being mitigated.
The issue isn't bloated websites as much as the web itself.