[cluckindan]

What important functionality do you feel is missing from the commonly used JS environments (node and browser) that is causing people to install it as a third party dependency?

The issue isn’t that the functionality doesn’t exist, it’s always backwards compatibility with versions where it did not yet exist.

[sidewndr46]

How can one have a backwards compatibility issue if the solution didn't exist yet?

[cluckindan]

Polyfills/ponyfills for functionality that has been specified but not yet (widely) implemented, or just missing from some blessed runtime at hand.