+1. After working on Elixir for a long time I missed the simple ruby way to do things and found myself running in circles to troubleshoot some basic 3rd party libraries. Going back to Ruby for my next side project.
Having used both Ruby and Elixir, this is exact opposite of my experience. I would say Elixir/Erlang is one of the best language from observability/debugging perspective. Immutability, per process heap, ability to trace any module/function call in production (recon), remote shell etc make it trivial to debug most of the issues. I have found memory leak in production from 3rd party library in less than 30 minutes. Just looking at the process list sorted by memory will tell which library is leaking (in majority of the cases), as most of the processes has single purpose.
Agree with your point about debugging being easier but in my case I ended up doing a lot of housekeeping for things that are easy in ruby. This time I'm only concerned about the speed of development and ruby to me is the winner
