I'm not a huge fan of Dialyzer myself. I would put it strongly in the "much better than nothing" category rather than the "usable and useful type system" category. I always write specs for my functions and types, and while they sometimes catch bugs, they're not quite as expressive as I would like them to be.

I suppose you could write Elixir in a style that was more type safe by writing in a less polymorphic or recursive style, but the language does not lend itself well to it. Structs and maps are mostly fine, discriminated unions less so.