No. That's nonsense. Everything is async in node because node is based on the V8 Javascript engine which is not thread safe. V8 is not thread safe because it was designed for web browsers, and browser rendering engines are also not thread safe.

People have tried to retcon node's choices as being based on some sort of deep technical justification, but that's not the case: its limits are the limits of the material it's made of, not a specific design choice.

If you look at more advanced VMs like the CLR or JVM then they support all modes of operation: synchronous/blocking (which is often what you want), synchronous/blocking with many threads, async with callbacks, async with continuations ... node only supports one. How is that better?