"A lot of batteries included" cannot be repeated enough. This is huge. Some languages you have to write your own. But the flip is also true. Take Node. For function X, there are 100 ill named "add ons" of variable quality and repute. Discoverability is a nightmare. Which-to-use in your mashup leads to paralysis analysis. I use a handful of libraries for some pretty large Python apps, but for so much of the basics, it's all in there. The quality and documentation vary a little, but the similarity/consistency is much better than you find in the wild. Even in Elixir (a much smaller universe than Node/JS), I experience this "15 poorly named packages that do the same thing in different ways".