Subtitles are essential for the preservation of languages and culture, being "Culturo-Diversity" as important for global human society, as Bio-Diversity is for nature and our planet.
I did not want to mention it in the video, but I consider translation and subtitling work to be under-valued and extremely underpaid. This creates a barrier to much more vastly dedicated translation and subtitling, limiting the sharing of our common human knowledge and wisdom. This is not well enough appreciated In this money-centered modern society, just as health-care or education are not.