It doesn't matter as much as you think. I believe this is in part due to how assertive most Elixir code tends to be. [1] These assertions not only aid the LSP and can cause compiler warnings/errors, they also help LLMs just like types do.

Still, every release now contains new type system features. Next up is full type inference. [2] After that will be typed structs.

[1] José Valim giving his balanced view on type systems: https://www.youtube.com/watch?v=giYbq4HmfGA

[2] https://hexdocs.pm/elixir/main/changelog.html

Pattern matching makes up for the lack of static typing for me. Combined with guard clauses it feels even stronger than static typing.

They are working on a type system.