1. Node has a lot of packages to be sure, but a lot of them are redundant, and a lot of them are packages that overcome some weakness in the Javascript standard library. Elixir doesn't have as many duplicates in its ecosystem, and its standard library is robust enough that you don't have to search for packaged one-liners to overcome some missing feature that should come standard with the language.
2. Node has access to Erlang's standard library and packages. It is also trivial to include external Erlang code and libraries in an Elixir application.
2/ Did you mean "Elixir has access to Erlang ..." rather than "Node...", I assume?
I'm well aware of that (I also use Java libraries quite a lot with JRuby etc, similarly), yet having worked with Erlang developers (in polyglot apps), I still personally find that there is more choice for me in both Node & Rubygems, compared to raw Erlang, at least for the topics we had to cover.
Well - I guess it depends on what your actual needs are, YMMV!
> where a single Elixir process will be able to use more RAM & all the cores, too.
I think you mean a "single instance of the BEAM" here as a single Elixir process is pegged to 1 CPU core.
This can lead to a more complicated architecture than with Elixir, where a single Elixir process will be able to use more RAM & all the cores, too.
On the other hand, I love the dynamism of the Elixir ecosystem, but it's not yet as rich as Node's one, and it's still harder to find a proficient Elixir developer, than a Node one.
But personally yes: the fundations of Elixir are very, very strong, and I'm investing in it completely (in addition to Ruby & Node, which I already use).