Erlang's not about lightweight processes and message passing
Without those lightweight processes that process messages sequentially from their  inbox these behaviors won't give the same concurrency guarantees.<p>I don't know why the author is turning this into a competition of whether processes are more important or behaviors - they both are parts of a well designed system that work well together.<p>GenServers etc can't be written equivalently in Go/Java since goroutines and Java threads (even the new virtual threads) are not pre-emptive, whereas Erlang processes are truly independent.