This is kind of why I've never bothered to look at it - everyone /says/ it's a wonderful thing, but... nobody uses it in production, or hobbies (apart from the diehard fans)
It might see the light of day at some point in the future, but if the past is anything to go by...
I'm familiar with Whatsapp and its relationship with erlang (there's RabbitMQ as well, which I always forget when asked..)
But they're the only real case studies
If I were to say "Go", people can point to big projects like Docker, Kubernetes, etcd, Googles internal use, and a few others (Uber?)
Erlang just doesn't have that sort of buy in, which is concerning because it's been around longer than Go (as a FOSS language), heck it's been around longer than Python (but it was proprietary back then)
Speaking as someone that's never used it, that's got "don't bother unless you've got an academic interest in it" written all over it
It might see the light of day at some point in the future, but if the past is anything to go by...