The problem actually existed before Unicode appeared. Terminals which supported Chinese, Japanese, or Korean characters have had to deal with 2 cell wide glyphs

The problem actually existed before Unicode appeared. Terminals which supported Chinese, Japanese, or Korean characters have had to deal with 2 cell wide glyphs, even for text encodings which use 1 byte per glyph. If you see the term "full width" character in old terminal related specs and documents, they are talking about 2 cell CJK glyphs/characters.