In my opinion, focusing on web frameworks (emulating ror,for example) as the the major reason to write libraries with elixir is self defeating. Elixir should have the larger goal of being useful for developing in up and coming fields as ai/ml etc..
Otherwise it will be stuck as another web dev language which I think is quite saturated at this point. At least 15 to 20 years of such web framework dev languages and their libraries are already in existence so why keep adding to it?