Elixir libraries are also pleasantly backwards compatible in my experience (with the occasional exception to be sure). At my company the effort required to maintain currency has been 1/10 that of Ruby in my experience.
I frequently hear that elixir lacks the 3rd party library support of Ruby. If you use sheer quantity as the criteria, then definitely, but in the 6 years I’ve been using Elixir, this has interestingly never gotten in my way. I’ve always either been able to find a library or the problem simply isn’t gnarly enough to deserve a library. Maybe I just haven’t picked the right problems with which to experience this lack though :).
All that to say I think Elixir and Clojure are very similar in these regards!