I do a lot of Elixir programming, which is different and not at the same time :-) . What I find is that it takes me longer to write the initial code than I might in, say, JavaScript, but that the refactoring and ongoing maintenance of code is significantly faster. This is because I think the functional & actor paradigms force you to think harder upfront, but once those decisions are made are easier to manipulate. For me personally, I'd take that trade since I'm either refactoring or maintaining much more frequently... but I understand there are other considerations which could drive a different preference.
Also, I'm sure my personal experience isn't necessarily true for everyone... so weight this anecdote accordingly.
One of the features I really like about the BEAM is that it solves the problem of organizing the topology of the applications I build. It's unlikely you're even close to doing this in other languages / frameworks.
The supervisor tree is one of the killer-app features of BEAM. I hit the benefits of this ALL the time. I notice how it keeps getting solved over and over again in unique ways that are half-baked. In some ways, this quote is what I'm hinting at, except, things don't even have to be concurrent. That's just a cherry-on-top.
"Virding's First Rule of Programming:
Any sufficiently complicated concurrent program in another language contains an ad hoc informally-specified bug-ridden slow implementation of half of Erlang."
I'd also argue that "sufficiently complicated" bar isn't very high.
There are matured ways to do multi-service outside of BEAM. I get that it's extra work vs something built in, but this is only an issue at large scale, and you'd probably need to set that up anyway unless every service is Erlang/Elixir.
A few things to keep in mind. This is a "labor of love" personal project... sure a large one... but that's what it is. Another thing to consider is that I go off standard Elixir practices in a number of different ways and for reasons™; in this sense the project isn't representative of what a typical Elixir project looks like.
When I say that things take longer for me to initially code, I'm not including "self-inflicted" time dealing with novel issues which arise from taking a less common path... which does have its own time cost. In my previous comment I'm only really thinking of the typical aspects of Elixir development time.
Finally, I do need to emphasize: for me the cost is worth it. Once I get to maintaining that now-developed code or doing refactors, so long as I'm not throwing away everything and starting from scratch, the development time for me is rather less than I have with code of similar complexity developed in other languages. All personal experience... but there you have it.
Also, I'm sure my personal experience isn't necessarily true for everyone... so weight this anecdote accordingly.