> There isn't really a CSV standard that defines the precise grammar of CSV.

Did you read the link going to a page literally titled: "Parsing JSON is a Minefield."?

JSON has a "precise" grammar intended to be human readable. The end result is a mess, vulnerable to attacks due to dissimilarities between different implementations.

Google put in significant engineering effort into "Ryu", a parsing library for double-precision floating point numbers: https://github.com/ulfjack/ryu

Why bother, you ask? Why would anyone bother to make floating point number parsing super efficient?

JSON.