I think it's more that the YouTube developers are US Americans who overwhelmingly speak only one language and naturally assume this is the case everywhere else.
This is a clear example where diversity of lived experiences make for a better product. I have no doubt that a young monolingual US developer can't imagine that many, if not most, people around the world are juggling between two or more languages multiple times a day. But it's obvious to anyone else.
This feels off to me. There are so many Indians in silicon Valley, most of which speak at least one Indian language (even if not as well as English) in addition to English, some from India, some whose parents or grandparents are from India. They're both there in higher levels and lower levels - they're throughout the company, and none of them stepped in? I don't think this makes sense.