Even if you disregard the modeling power that you can get from this there is an upper bound on any elixir project after which any work on it becomes less and less easy to do, as with all languages that lack a static type system. We write assertive elixir code as much as we can, but that doesn't mean that you can actually guarantee anything about a code path that is less traveled.
dialyzer is also not the answer. Oftentimes we'll find ourselves in a situation where dialyzer complains because someone who made a major library simply doesn't use dialyzer. You might wonder why they don't in that case, because it would pick this particular issue up very easily, but the next time you run into some garbage error that dialyzer spat out that you are instantly reminded that you can neither trust it to be correct or safe, so people turn it off.
Elixir has upsides: I think it's solidly the best language for creating servers of different kinds, but it's near useless after you pass a fairly short distance with it. I would absolutely never, in my personal endeavors (as opposed to my working contract) write an elixir server that actually tries to do anything meaningful itself other than just route messages to other servers.
