I'd argue that in the vast majority of cases, anything 'missing' from the ecosystem is probably one of those gems that probably shouldn't be a project dependenc

I'd argue that in the vast majority of cases, anything 'missing' from the ecosystem is probably one of those gems that probably shouldn't be a project dependency anyway. That doesn't mean it won't filter its way over to the Elixir ecosystem at some point, but I don't think you'll find any of the major pieces missing.