the elixir ecosystem doesn't have the "library for anything you could possibly need" benefit that you find with rails (and probably django too)

Unfortunately, I did not! The reason for choosing Rust was mostly because of the lack of nulls and the way it handles errors. Basically the Option and Result types. And because you have so much low level control with a language that otherwise feels quite like a high level language.

I did try Erlang around 2017-2018 and quite liked it. The Joe Armstrong book is one of my favorite programming books. Perhaps I'll have a look at Elixir if I ever need to build something new from scratch.