I think new languages wont be able to break in the top 10 without a mega corp pushing them. The market is too saturated and there is a language for everything under the sun. Elixir is just facing too much competition for web stuff and doesnt enjoy Google pushing it.
I don't think it's necessary for a language to be in the top 10 to be considered a success. If the people who use it, wouldn't use anything else, then that is the success.
As long as you're aware that hiring and maintaining will be significantly harder then yes you're right. But that also means there's no reason to choose esoteric tech X for yet another CRUD app; you would pick Erlang/Elixir when it actually makes sense and only then.
