Erlang (and quite frankly Elixir) really has always seemed like it was, in some form, ahead of its time. I really hope it spikes in popularity.
Any day now...
It won‘t but I don‘t get why. The thesis is genius, it even starts with an philosophy and an attempt to formalize software architecture.
Erlang was invented at Ericsson, used for certain phone switches, it was tremendously successful at what it was built to do, and still it‘s not used anymore in their newer switches.
Why?
Whatsapp (and IIRC Wechat) were built in Erlang. I think Discord is also Elixir/Rust
My take is that when the advantage to be gained is a superior architecture or set of abstractions that can be built by a small core of engineers then language choice can be an advantage. When the business needs to scale into the real world long tail of integrations, infrastructure, clients etc then throwing bodies at the problem can be an advantage and then ecosystem and talent pool outweigh original language gains.
Sharp tools are at their best in a smaller more focused team... But in software, building the right architecture can in some cases be all the difference
because the benefits aren't that much greater, and great features in languages like erlang and haskell end up (to some extent) in popular languages (which further reduces the need to adopt such languages)