I love elixir but gleam looks more easy to learn if you come from javascript
If you write JavaScript like it’s Java and really lean into OO, then Elixir will be more alien and force you to learn some new patterns.
The only major difference between them is the typing and the syntax I'd say.
If I were to try to make the argument for you, I'd point to some of Elixir's more powerful abstractions like protocols and macros as a reason Elixir might be harder for JS devs. In reality, though, I found it very straightforward to learn as a JS dev, and that was back in 2016 when the documentation was much worse.