That's a very valid concern.
My personal opinion:
Yes, the package system is pretty small. That's why it depends what kind of project you are gonna write and how much time you have. Ruby has a lot of gems, but many of them are buggy and deprecated... Proof: https://github.com/rubysherpas/paranoia
I think that Elixir is gonna catch up. If you write a project where you need to use a lot of external libraries probably Ruby is better. If you don't need to rely on the external dependencies too much and you want to/have to write your own code(libs), imo, Elixir is a better option. It also depends on a project, lots of external api calls, webhooks, real time chatrooms, etc. I think Elixir is gonna be a better option.
One thing more, because Elixir's code is much easier to deal with, it's easier to fork and fix deprecated lib than in Ruby(Rails).
I think that Elixir is gonna catch up. If you write a project where you need to use a lot of external libraries probably Ruby is better. If you don't need to rely on the external dependencies too much and you want to/have to write your own code(libs), imo, Elixir is a better option. It also depends on a project, lots of external api calls, webhooks, real time chatrooms, etc. I think Elixir is gonna be a better option.
One thing more, because Elixir's code is much easier to deal with, it's easier to fork and fix deprecated lib than in Ruby(Rails).
It's just my opinion.