little anecdote: I did a couple of personal projects in elm in 2017. one thing I'm thankful for it taught me functional programming. Elm was easy to start with for someone new to functional programming. it also taught me, one important lesson - the market doesn't really care. a company when you're looking for a gig doesn't care if you know elm, it wants you to know the 'framework'they're using currently. so yeah, I see elm being a dead end. either people using it already solved product/market fit. but for a startup getting off the ground - elm offers no benefits at all compared to js.
I had the opposite experience with my last job interview. I didn't know any Ember but I did know Elm (and other languages and frameworks). My enthusiasm about Elm absolutely contributed to my being hired and my lack of Ember knowledge didn't hurt me. This was what the hiring manager told me.
