I think binary formats have many advantages. Not only for numbers but other data as well, including data that contains text (to avoid needing escaping, etc; and

I think binary formats have many advantages. Not only for numbers but other data as well, including data that contains text (to avoid needing escaping, etc; and to declare what character sets are being used if that is necessary), and other structures. (For some of my stuff I use a variant of DER, which adds a few new types such as key/value list type.)