[felixgallo]

I don't think either of those are particularly problematic. The actor model as implemented by Erlang is concrete and robust enough. The big problems with the actor model are, in my opinion, around (1) speed optimizations for immutable memory and message passing (currently, there's a great deal of copying and pointer chasing involved, which can be slow and is a ripe area for optimization), (2) (for Erlang) speed and QOL improvements for math and strings (Erlang historically is not about fast math or string handling, but both of those do comprise a great deal of general purpose programming), (3) (for Erlang) operational QOL misc improvements (e.g. existing distribution, ets, amnesia, failover, hot upgrade, node deployment, build process range from arcane (amnesia, hot upgrades, etc.all the way up to covered-in-terrifying-spiders (e.g. debugging queuing issues, rebar3))

[RossBencina]

There is no lineage between The Actor Model and Erlang. The creators of Erlang are on record as having never heard of the Actor Model (as developed by Hewitt, Agha and colleagues at MIT). None of the points you make (including the first one) are a part of any formal definition or elaboration of the Actor Model that I have seen, which was one of my points: there is no unified theory of the Actor Model that addresses all of the practical issues.

With respect to your point (1), you might be interested in Pony, which has been discussed here from time to time, most recently: https://news.ycombinator.com/item?id=44719413 Of course there are other actor-based systems in wide use such as Akka.