A basic scalar pair in ᴊꜱᴏɴ is "key":"value", or "key":value, so a 4 or 6 character overhead. xᴇɴᴏɴ is <key=value>, 3 characters. In my tests xᴇɴᴏɴ IS more terse.
You are being criticized for quality and your response is to fixate on one parameter being better. It's as if you were overweighing that parameter or ignoring the other million of parameters, which is what makes your proposal so out of place.
Suppose that you come to the world economic forum, and you propose a new coin you call the GeneThomas coin. When people criticize or laugh about your idea, you respond that "The coin IS greener! It really is and I can prove it". Man, you are just showing that you don't understand anything about what makes a currency good or popular.
Just find your niche in green coins, but don't try to compete with the US dollar or bitcoin cause you'll lose