I get your point. Even without message passing, just in process calculation in Erlang/Elixir is also pretty slow compared to Java. But in the domain of Web pro

I get your point. Even without message passing, just in process calculation in Erlang/Elixir is also pretty slow compared to Java. But in the domain of Web programming, scheduling efficiency is much more important than the speed of execution. If it is a huge batch operation on a single machine, Erlang/Elixir would be terrible. Similarly, for React there's fiber mechanism -- it's worse according to benchmark, while the user would get a better experience due to a better schedule.