(This is admittedly old and anecdotal experience). I had a Spanish girlfriend in the past, and while learning Spanish it struck how their was a vast parallel world in the ‘Spanish hemisphere’ with very few touchpoints to the English speaking world. Own news, own TV content, own culture. At the time Spanish was the 2nd most used native language after Chinese.
These days I have the impression there are quite a few Chinese projects on Github, with all issue content and code comments in Chinese. It is a big barrier to participate.