Based on vim's word wrapping (which shows blank spaces instead of completely hiding it), they're being rendered at the end of the line. So if that is accurate it kind of makes sense that for UI-based interactions to be a one-character offset.

How many direction marks can we see in this hidden text?

I’m actually complaining about more “advanced” features like hiding text (see my comment above) or zalgoing it.

And of course endless variations of skin color and gender of three people in a pictogram of a family or something, which is purely a product of a specific subculture that doesn’t have anything in common with text/charset.

If unicode cared about characters, which happens to be an evolving but finite set, it would simply include them all, together with exactly two direction specifiers. Instead it created a language/format/tag system within itself to build characters most of which make zero sense to anyone in the world, except for grapheme linguists, if that job title even exists.

It will eventually overengineer itself into a set bigger than the set of all real characters, if not yet.

Practicality and implications of such system is clearly demonstrated by the $subj.

You're right, of course. The point was glibly making was that Unicode has a lot of stuff in it, and you're not necessarily stomping on someone's ability to communicate by removing part if it.

I'm also concerned by having to normalize representations that use combining character etc. but I will add that there are assumptions that you can break just by including weird charsets.

For example the space character in Ogham, U+1680 is considered whitespace, but may not be invisible, ultimately because of the mechanics of writing something that's like the branches coming off a tree though carved around a large stone. That might be annoying to think about when you're designing a login page.

I mean, we can just make the languages simpler? We can also remove all the hundred different ways to pronounce English sounds. All elementary students will thank you for it xD

I know you're being funny, but that's sort of the point. There's an important "use-mention" distinction when it comes to historical character sets. You surely could try to communicate in authentic Unicode Akkadian (𒀝𒅗𒁺𒌑(𒌝) but what's much more likely is that you really just want to refer to characters or short strings thereof while communicating anything else in a modern living language like English. I don't want to stop someone from trying to revive the language for fun or profit, but I think there's an important distinction between cases of primarily historical interest like that, and cases that are awkward but genuine like Inuktut.