Wow, this is the exact opposite of my experience. I can't imagine a company trying to hire Elixir developers and having any success unless they're willing to hire remote developers. I know a lot of folks in the community and literally everyone is remote...
I feel that there are more remote Elixir jobs than ever. I get a lot of offers without actively searching, most often it's sole Elixir or Elixir + Ruby (unsurprising) combo.
It's a mix of things. A lot of the b2c stuff uses big partners that are already dominant in eGrocery. However the tooling around the ad placement, fulfillment, product cataloging, b2b sales, sales intelligence and consumer profiling all make use of Elixir.
Basically we use React for most front ends, Python for data engineering/data science, and Elixir for everything else.