[Klathmon]

Bolting on the newer features as additional packages has a few downsides in my experience:

* Increased complexity. So now in order to use request in a modern JS ecosystem, you need to install request, and request-promise-native, which itself installs request-promise-core, which all 3 then combine to use. Which do you look for to find documentation? Which do you look at when you have bugs? How does interop happen with other 3rd party libraries? Does every other lib that works with request have to handle all the official wrappers or just the main? And good god what happens when breaking changes are made to one of them? Everything is just a lot more complicated here.

* Only so much can be easily patched on. Things like streams are pretty complicated, and writing a complicated (and often slow) runtime transformation of a stream to an async iterator, both of which don't have complete 100% matches for all of their features, means that everything is now using a sub-par incomplete interface. The main application can't implement features which take advantage of the new syntax, and the wrapper can't always represent the old ways of working perfectly.

Basically, it's a leaky abstraction in most cases, which is slower, uses more memory, and is a lot more complex.