When comparing Elixir vs Racket, the Slant community recommends Racket for most people. In the question“What is the best programming language to learn first?” Racket is ranked 3rd while Elixir is ranked 4th. The most important reason people chose Racket is:
Includes several free online books and great documentation.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Great documentation
Elixir's documentation is very good. It covers everything and always helps solving any problem you may have. It's also always available from the terminal.
Pro Great for concurrency
Leverages the existing Erlang BEAM VM

Pro Easy to download libraries
Comes with built in build tool called "mix". This will automatically download libraries and put them in the scope of the application when you add them to the "deps" function and run mix deps.get

Pro Great getting started tutorials
The tutorials are very clear and concise (even for a person not used to functional programming). Plus they are also very mobile friendly.

Pro Syntax is similar to Ruby, making it familiar for people used to OOP
All of the benefits of Erlang; without as steep a learning curve of prolog based syntax. Elixir is heavily inspired by Ruby's syntax which many people love.
Pro Full access to Erlang functions
You can call Erlang functions directly without any overhead: https://elixir-lang.org/getting-started/erlang-libraries.html
Pro Powerful metaprogramming
Write code that writes code with Elixir macros. Macros make metaprogramming possible and define the language itself.
Pro Free Resources to Learn
Includes several free online books and great documentation.
Pro Racket was designed to teach functional programming from the start
Racket is based on Scheme (LISP Family) and is very similar to Clojure. So there are a ton of (). The reason it is easier to learn is that it is not trying to be "Pure" if there is even such a thing in terms of Functional Programming. The great thing about Racket is it has everything included. You get DrRacket for developing programs. You want to add a picture to your software you can insert pictures. If you want to add libraries just open the package manager. The Syntax is an opinion but it really does feel easier to see what is happening since everything is in brackets)
Racket is a really a Programming Language for making Programming Languages. So there are smaller syntax Racket called Student Racket which makes things easier to pick up.
Pro Realm of Racket is an excellent entry-level guidebook
Realm of Racket teaches the big-bang approach for managing world state. It does so by walking the reader through the development of small games. There are few guidebooks that are as useful and entertaining.
Pro Easily embeddable
Racket is famously embedded in the game engine underlying Naughty Dog's Uncharted and The Last of Us games, because it proved to be so easy to embed.
Pro Great RPEL IDEA included Dr. Racket
Pro Active community
Racket has an active community of users/developers that makes it easy to get help when needed.
Cons
Con Some design choices may seem strange
Some design choices could have been a little more appealing, for example: using "do...end" comes natural in Ruby for blocks but Elixir uses them for everything and it looks pretty weird:
Enum.map [1, 2, 3], fn(x) -> x * 2 end
or
receive do
{:hello, msg} -> msg
{:world, msg} -> "won't match"
end