I won't even touch the fact that what you're talking about is just a stylistic difference, rather than a language based one, and will instead say this: What if you want the cyrillic letter А and the latin letter A, which are not just the same glyph, but literally visually identical looking in the same document? Oh wait both of those have separate UTF-8 codepoints. But if you want chinese and japanese characters which do not look identical in the same document, you have to resort to changing fonts? What if you're using an encoding that doesn't support specifying fonts? Your non-response doesn't solve anything and helps no one

Some fonts allow for both alternatives in them