One of the early things I learned when I first coded for accessibility was to not try to make a separate “Accessible version/mode” of a site

This. It's so easy now, especially with HTML5, to make an accessible website. When I redesigned my personal website it was ridiculously easy to make it accessible, testing tab navigation, devtools accessibility checks, a screen reader and webaim's site to verify that each page was structured in a sensible way. I don't have any impairments to validate how useful these would be, but it took comparatively not much time ensuring the best effort was put forward in making the site accessible.

I can't see why Reddit, a company with people paid to work on the site and app, hasn't already done it. Empty responses such as "we can do better" and failing to engage with the communities on their platform that rely on their APIs to make Reddit accessible to all (such as those with volunteers transcribing content for blind users) just lays it bare that Reddit doesn't actually care