Unicode (ISO/IEC 10646) is without doubt a hugely successful project. But like every huge project, it keeps nurturing itself ad infinitum, and is becoming absurd in the process (for example, Unicode has also captured emojis). As Unicode is covering more and more symbols all the time, it becomes less and less useful for its original purpose to communicate the character set encoding standard used in a document. Eg a basic info about a document is whether it can be rendered with a given font, but Unicode (or a character encoding information such as "utf-8") totally fails this basic use case, and one has to build small ad-hoc subsets within Unicode for this purpose instead.