My hunch echoes that of other commenters here. That is, it seems like many core libraries have been quite steady and "complete" for a while now, and many people are just using them today to get work done. That isn't to say the language ecosystem would have stagnated, however.

One interesting piece of data comes from Elixirforum.com, arguably the central hub for the Elixir community. In their recent MOTY update [1], they announced that "..to give you an idea of how far we’ve come and how fast Elixir has been growing, in the forum’s first year we served just over 1M pages for the entire year, now, we’re serving a million a month".

The official Elixir language site has also been steadily accumulating more and more case studies [2], which one might consider as sign of health in terms of Elixir being used in the industry. Obviously it's only the success stories being told, though.

Recent news regarding Nx [3], Livebook and Axon suggest there are new doors being opened for Elixir as a language in the AI/ML space. This expands what the language can be used for, and as such, could be considered as another sign of health and vibrancy in the ecosystem.

Looking at something like GitHut [4], it seems like Elixir has maintained a steady position on its rankings in terms of pull requests. This suggests that usage of the language hasn't declined in the recent past.

Lastly, the 10-year Dashbit blog post [5] by José might highlight some other development. While "development" is not synonymous with "health", I feel like the contents can suggest lack of death :)

[1] - https://elixirforum.com/t/2020-motys-and-our-5th-birthday-up... [2] - https://elixir-lang.org/cases.html [3] - https://dashbit.co/blog/nx-numerical-elixir-is-now-publicly-... [4] - https://madnight.github.io/githut/#/pull_requests/2020/4 [5] - https://dashbit.co/blog/ten-years-ish-of-elixir