[wakawaka28]

The reason that wasn't done is because Unicode is not really in older C++ standards. I think it may have been added to C++23 but I am not familiar with that. There are many partial solutions in older C++ but if you want to do it well then you need to get a library for it from somewhere, or else (possibly) wait for a new standard.

Unicode and character encodings are pretty esoteric. So are fonts. The stuff is technically everywhere and fundamental, but there are many encodings, technical details, etc. And most programmers only care about one language, or else only use UTF-8 with the most basic chars (the ones that agree with ASCII). That isn't terrible. You only need what you actually need. Most programs don't strictly have to be built for multiple random languages, and there is kind of a standard methodology to learn before you can do that.