Instead of that sorry excuse of an article, here is the proper long-read about spaces.
Albeit in Russian, all modern browsers support live translation — should be fine.
https://type.today/ru/journal/spaces
Update: in English https://type.today/en/journal/spaces
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BTW typography is very important to Russian designers and developers.
Many install special typography layout (with “right alt” layer for the symbols) to always enter correct m-dashes, quotes, and what have you.
https://ilyabirman.ru/typography-layout/
There is even an ongoing meme with a woman crying “I don’t deserve such treatment, that’s how I’ve always written” when her flawless typography was considered ChatGPT in the making: