But then again the internet is everywhere now: desktop, servers, watches, washing machines, industrial systems, sensors ... So "internet language" is a somewhat pointless term.
So I think it is a useful term, and captures the things Go is good at surprisingly well.
It's feels like they didn't want to dog food it outside of their servers, though.
Quite a few of us are, fwiw. I personally have done all three, Tailscale uses Gio UI for their mobile apps, and a fair amount of games have used https://ebitengine.org to release for Xbox/Nintendo Switch/Mobile/Webassembly/Cross-platform PC.