No it's not. You could describe Elixir, with a lot of caveats, as a "ruby-fied Erlang" because a lot of the niceties are there. It's faster than Ruby, but it's totally not Ruby.

Perhaps the "faster ruby" moniker could be arguably assigned to Crystal.

Not really, it's a pretty different language that in some ways looks superficially like ruby.

To start with, ruby is object-oriented, everything in ruby is an Object of a Class; while Elixir is functional, and doesn't even have Objects and Classes.

But sure, other languages than ruby certainly exist, some of which will be faster, in various use cases/contexts!

Yes but it has its own ecosystem. It can't use gems from Ruby. The main selling point for this is because they use the Erlang VM and that thing is uncrashable. Thought from the start to be fault-tolerant and distributed.

So boosting the speed of Ruby itself is always a good news for everybody using it.