Why not one package per line of code? One package per expression? Surely, someone will want to reuse var x = a + b.

   const {get} = require("underscore.get");

   get(obj, 'a[0].b', defaultValue);

If your language requires this [1] just to be able to subscript things without going bonkers, it may be time for a new language.

[1] https://github.com/NarHakobyan/underscore.get