pythonistah

Perhaps they only collect data from browsers hitting their web site?

The data behind their world wide browser stats is questionable. - their combined IE and Edge market share totals to only 8%.

On https://www.netmarketshare.com combined IE market share is 31% and Edge is 5%.

What percentage of browsers in use implement Proxy and Promise classes? 40 percent?

It uses Proxy and Promise classes.

The line numbers in BASIC were arbitrary. People often started at higher numbers and jumped by 10 in case they had to put code or comments before or between lines.

The parentheses-less javascript dialect in the title of this HN article relies on ES6 and uses 6 characters:

    !+[]`$

The parent link above is ES5 and uses 8 characters:

    !+[](){}

The jsfuck.com ES6 dialect uses 6 characters:

    !+[]()

jsfuck was previously ES5 but they now rely on ES6isms to shorten their code.