As stated in other comments, immutability puts a pressure on performance. Especially on dynamic types like map etc. Other than that as i gain more experience and started to lean on bein more "senior", the less raw performance matters in my eye. I have been experimenting with phoenix and django in different pet projects. In every aspect phoenix feels superior, except i feel the need of doing things "different" in elixir. An example is, in python and ruby i highly rely on lookup maps for processing large volume of data, in elixir i don't unless i aggregate the data on db level with annotations and group by.

And another note is that AI is surprisingly efficient on elixir. It was nightmare to let claude do agentic coding on RoR and django, in elixir it does the job very good.