Video works because Hinglish is how tech-talk in (many, not all) companies works.
But you’d never see a technical doc in any of the these companies in Hindi, because you can’t even translate simple terms like Server or package-management. Even if you find acceptable translations, they aren’t immediately obvious, because nobody has heard them before.
In a Python video, you might hear: “मेरा code requests library से Google server को HTTP request भेजता हैं” (My code uses the requests library to send HTTP requests to Google”.
It works on video, but it doesn’t on text because nobody is used to reading this in Hindi in the first place.
When I was young I used to play some MSX games in Japanese, the language doesn't really matter for a lot of these 1980s games, and you would frequently see English words and terms written in Latin characters used all over the place.
Why won't this work for Hindi? Are people not familiar with these characters? Or is there just no tradition of doing so?
It's quite annoying as a learner, since it can make it difficult to map back to devnagārī (resp. devnagari) to look up a new word, for example. (It's almost entirely true to say that devnagārī script is phonetic, so if you write कुछ and I don't know the word, I know how to pronounce it without knowing what it means, and can ask someone or look it up, which is a great feature that English of course doesn't have at all, and while Hindi phonetic approximation in the alphabet might get closer, it's still non-standard and different typers will spell words differently.)
Nobody bothers to use them.
Same for Urdu https://en.wikipedia.org/wiki/Roman_Urdu