> Its numbers representation is double-precision floating-point, meaning it's incredibly imprecise and limited.

Maybe somebody can elaborate and what the author might have actually meant?

I think JSON numbers are not necessarily double-precision, at least I don't think I've ever seen them specifically described this way. In JavaScript, however, numbers are double-precision, there are no real integers in JavaScript. So maybe the author misrepresented JSON numbers because JavaScript numbers are double-precision. But that isn't necessarily the case AFAIK.