Yyyy... Erlang has great adoption - examples:

- Ericsson (they designed Erlang) is using it for its mobile products/networks. Approx 40% of all mobile traffic worldwide goes through Ericsson's infra.

- WhatsApp used/uses Erlang - again millions (billions?) of users

- Bet365 / Klarna use Erlang - millions of users

- from OSS, RabbitMQ, is written in Erlang

I could go on... Erlang has great adoption, but it's probably smaller than, e.g. Python, due to Erlang's specific applications.