Exercism's elixir path have Zero maintainer, should I continue?

I would say that instead of “maintainers” you should be more concerned about the mentors because those are the people that will be volunteering to review your submissions, and there’s plenty of those: https://exercism.io/tracks/elixir/mentors

There are active maintainers, though they have not opted in to be listed on the web site.

There are also active mentors.

So you can safely do exercism. Be aware though, that there is a major PR in review, that will change exercise structure to follow mix project convention rather than beeing loose files.

I am using the elixir track on exercism (albeit infrequently) and all of my submissions have been followed up by a mentor - last one was a couple of weeks ago or so. In fact, my mentor is amazing

Just to +1 @NobbZ, there are lots of active mentors on exercism.io! A great place to learn!

It is also a great place to contribute to as well if looking for open source opportunities!

Also it is to say, that exercism currently searches for volunteers who help to bring the tracks to the next level.

This call for volunteers is open for all 50+ languages/tracks, but I will only link to the elixir one:

https://github.com/exercism/elixir/issues/524

This! If you want to help other people learning Elixir feel free to join Exercism as a mentor. It’s a great experience because you always end up reading a lot more about Elixir just to make sure that whatever feedback you’re giving to the student is 100% correct.
You don’t need need to finish all exercises first, I’m currently a mentor and still have most of the Hard exercises to do.

All in all it’s great feeling getting to help other people learn this language