In my experience I’ve seen JS on the backend really only used for lambda functions, to run socketio for some chat-like feature or for pre-rendering React components.
I work for a Fortune 50 and my team’s product is JS frontend and backend. JS all the way down :)
Might just be my area then (Berlin) I hardly see job ads for JS on the backend.
Node is massive in London so, yes, your experience has an element of local bias.
Wow we must be in separate Berlins because I see tons of JS backends. My impression is Javascript & Python are competing for most popular backend.
Quite possible that I live in my bubble! I see a lot of React & React Native but hadn't seen so much on the backend.
Seconded that in another comment in this thread. Lots of "fullstack JS saves you money since you can hire the same devs for web, backend & mobile" in Berlin, with varying success