I disagree that Erlang is an ur-language (it's too close to the Self and Prolog ur-languages to be its own, IMO), but I do agree that OTP/ERTS could be a sort o

I disagree that Erlang is an ur-language (it's too close to the Self and Prolog ur-languages to be its own, IMO), but I do agree that OTP/ERTS could be a sort of ur-framework or ur-runtime, for exactly the reasons you describe: even explicit attempts to implement "Erlang-style concurrency in $LANGUAGE" routinely only cover some superficial "yeah we've got actors that pass messages and maybe supervise one another" without covering preemptive multitasking, hot-reloading of functions, distribution across nodes, and the myriad other features that give Erlang its reputation for extreme fault-tolerance.