>All parallelism is asynchronous, but not all "asynchrony" is parallel.

Sure, but my comment was not about parallelism compared to asynchronous, but about the idea that Javascript is above the "blocking first mindset".

Javascript depends on a blocking (single-threaded, run-to-completion) backend. The asynchronicity on top of this blocking layer is an abstraction based on cooperative yielding.

Whereas e.g. Erlang's asynchronicity is part of the runtime model itself.