I would believe if someone said it was completely organic. It's just how Internet is and how social graphs build up. The typical American notion that the Internet is nearly 100% dominated by American English socio-cultural platform and English is the foundational language of the world's all cognitive processing is just an annoying megalomaniac hallucination.

English is used as a lot as a fallback language for inter-cultural exchanges. In that sense it's kind of dominating, but that's it. Intra-cultural communications happens in local languages, and even if that preferred language happened to be one of en-* locales, that only means everyone is functionally bilingual, and it doesn't mean cultural informational borders don't exist. Data still only goes through bridging connections.