The only universal, fixed-size encoding is UTF-32, which, as you can imagine, is very wasteful on space for ASCII text. Like it or not, most of the interesting

The only universal, fixed-size encoding is UTF-32, which, as you can imagine, is very wasteful on space for ASCII text. Like it or not, most of the interesting strings in a given program are probably ASCII. UTF-16 is not a fixed-size encoding thanks to surrogate pairs. UCS-2 is a fixed-size encoding but can’t represent code points outside the BMP (such as emoji) which makes it unsuitable for many applications. Besides, most of the time individual code points aren’t what you care about anyway, so the cost of a variable-sized encoding like UTF-8 is only a small part of the overall work you need to support international text.