And don't forget script number four in Japanese: Latin letters! Used for all sorts of odds and ends not covered by the other scripts; mostly (abbreviations of) names like 「ＩＢＭ」. These conveniently come in full-width versions for use with kanji, hiragana, and katakana, but this of course won't stop anyone from using the basic letters we're using here. So in the hypothetical case where Unicode is a thing, but the lingua franca of software engineering is Japanese instead of English, you might end up with variables named:

    変数
    へんすう
    ヘンスウ (or even ﾍﾝｽｳ)
    ｖａｒｉａｂｌｅ
    ＶＡＲＩＡＢＬＥ
    variable
    VARIABLE

…and all the additional snakes and camels varying the notations further.

Without capitalization you would not able to have a class Thing with an instance thing.

It's a short article but maybe capitals have been useful overall