Most languages block by default, so backpressure is much easier to model: just don't read until you need more data and the sender will block. But in JS the rec

Most languages block by default, so backpressure is much easier to model: just don't read until you need more data and the sender will block. But in JS the receiving end will just keep firing off data events until you pause it, or use something like reactive streams to request data as you're ready for it. That's my understanding of the situation at least.