Is it? Just tried it in Safari, Firefox and Chrome on a iPhone 12 Mini and I can read all the text? Obviously it isn't formatted, as it's raw markdown, just like what parent's recommended 3rd party platform does, but nothing is cut off or missing for me.

Actually, trying to load that previous platform on my phone makes it worse for readability, seems there is ~10% less width and not as efficient use of vertical space. Together with both being unformatted markdown, I think the raw GitHub URL seems to render better on mobile, at least small ones like my mini.