> Why should our advanced computers not be capable of handling the most basics of communication with every person on Earth?

I'd argue that ASCII in English is probably one of the more basic forms of communication with people that you can implement, due to how widely supported the character set is and how many people know English; no other pairing will get you as close to having your device be usable by a global audience than that pairing. Of course, that doesn't answer your question, so let me try again.

Because there are devices out there which simply don't need to do this. Not every computer out there is an advanced one. Not every computer out there will interface with every person on Earth. A lot of complexity would be introduced for no gain in many situations, therefore it makes sense to choose the simplest option.

For a contrast, allow me to show you GNU Unifont, which attempts to encapsulate all of Unicode BMP, the font weighs about 12 megabytes which is more memory than some devices actually have to use: http://unifoundry.com/unifont/index.html

From a different angle - it would be nice if all devices were able to do this, but there are so many different languages, types of writing and characters, that supporting all of them will be too troublesome, since the underlying programming languages, the ecosystems around them and libraries won't support them out of the box either.

Not supporting those at the lowest levels of abstraction means that you'll be trying to tack the support on later, like what moment.js attempts to do with the date and time functionality within JavaScript. And that's just a web application example, whereas in actuality these problems are probably most pronounced in embedded devices.

> Should we also drop accessibility?

This does feel like a bit of a strawman, but i'd like to suggest that many radios, thermostats and a variety of embedded/IoT devices don't have a lot of consideration given to accessibility in the first place. I can't recall the time when i could control any of those devices with my voice (apart from integrations with smart systems to control the home, though currently those are a rarity, maybe things will improve in 20 years).

I actually recall a radio once that attempted to support multiple languages on a LED display ( the kind that shows numbers typically, by lighting up segments on it, much like this: http://www.picmicrolab.com/wp-content/uploads/2017/06/Alphan... ). Let me tell you that their attempt at supporting Russian wasn't legible and as a consequence i simply couldn't figure out how to switch back to English, which was at least a little bit more readable in comparison. I fear the day when someone attempts to encode kanji in a similarly limited environment to results that actually make the device less accessible.

I might be horribly misdirected, but that's my answer to you - we shouldn't attempt to do things that aren't feasible with our current technologies, since language support is currently rotten to the core in many of them. Given that this support isn't available out of the box, you'd be pretty hard pressed to support multiple languages in your little Arduino project with a LED display, especially because attempting to do so would make you miss out on actually making it do what you want it to.

Maybe some day i'll just be able to put this in my codebase:

  printOnScreen(translate("Device not connected!", getCurrentLanguage()))

And have simple translations be made during compile time into all of the languages that the little project should feasily support (with localization files, which can be edited and then transferred over to the device alongside executables), but until something like that becomes an actual reality in all forms of computing, it's probably not worth it.

Domains in which the above comment doesn't hold entirely true:

  - desktop computing (even if translations are often poor and OS support for localization can be lacking)
  - web development (most large frameworks support plugins for localization, yet loading the localization from files outside of build time compiled ones still is not widely supported)
  - mobile computing (given that OSes like Android are pretty decent in this regard)