They're kind of solving different problems. It's a bit like TypeScript vs Elm or PureScript: one is a type system overlaid onto an existing language with its own rich ecosystem and set of idioms, and the other is a new language that targets the same underlying platform but has different idioms and semantics for static analysis.
If you already have lots of Elixir in production, or you enjoy Elixir's highly dynamic approach to solving problems and would like to get some additional safety for free then sticking with Elixir is a no-brainer!
If you'd like a simpler language with tighter static analysis guarantees while still being able to dip into the wider ecosystem then you might prefer Gleam.
Ultimately I think the two languages have very different philosophies and idioms, folks will naturally find themselves preferring one or the other ^.^
If you already have lots of Elixir in production, or you enjoy Elixir's highly dynamic approach to solving problems and would like to get some additional safety for free then sticking with Elixir is a no-brainer!
If you'd like a simpler language with tighter static analysis guarantees while still being able to dip into the wider ecosystem then you might prefer Gleam.
Ultimately I think the two languages have very different philosophies and idioms, folks will naturally find themselves preferring one or the other ^.^