Had the JSON standard supported ECMAScript array holes [1,,,2,,3] this grammar shortcut would not have been possible. But luckily that's not the case.
But the only reason to get rid of commas is to eliminate the trailing comma problem, which only occurs when hand-editing JSON. Replacing that with whitespace, or worse both whitespace and commas, would be a lot more prone to hand-editing errors, I think, than would the much less drastic change of allowing trailing commas. Or better still of just leaving JSON as is and letting people use a more robust protocol, if that fits their needs, or pre-parsing whatever special snowflake variations they want into standards-compliant JSON.
I'm more or less in agreement with the commenter on his site who said
> this entire proposal pretty much comes down to "I like JSON, but need more and am too lazy to write the extra 3 line wrapper to process type 'x'." I'd say no thanks. https://www.tbray.org/ongoing/When/201x/2016/08/20/Fixing-JS...