This is the kind of thing I'm talking about though... we go from "Erlang is a piece of cake for distributed systems" to some pretty advanced concepts and telling people to "roll your own" for an extremely common use case: not wanting your entire application to be taken down by an unreachable external service.
Back in the day, I found this to be a pretty good 'circuit breaker' type of thing: https://github.com/jlouis/fuse
I wrote something similar for the (OTP) application level: https://github.com/davidw/hardcore
In fact, I am writing this week a dynamic process pool in Elixir which is so peculiar in its requirements I don't think I've ever seen anywhere, and it's in total 500 lines of code spread over 2 GenServers (+ Registry and DynamicSupervisor). I reckon it would easily be 25x as much in C++ or Rust.
If you want exponential backoff, I suppose it should be pretty easy to implement with a custom Supervisor (though the best practice would be to have a sidecar GenServer to deal with the backoff/alerting business rules, and using a regular Supervisor.)