I’d like to see per 100g standardized in a second column like it is done in Mexico so that you can actually compare products regardless of what they say their serving size is (first column).
And don't blame lobbyists; they should be lobbying, just as a public defender should be defending their client. The people deciding the wrong thing after all lobbying has happened are to blame, especially given they're funded by mandatory taxes.
21 CFR § 101.9(b) defines general procedures for determining serving sizes: https://www.law.cornell.edu/cfr/text/21/101.9
21 CFR § 101.12 defines specific "reference amounts" for particular food categories: https://www.law.cornell.edu/cfr/text/21/101.12
See, for instance, § 101.9(b)(6) which says: "A product that is packaged and sold individually that contains less than 200 percent of the applicable reference amount must be considered to be a single-serving container, and the entire content of the product must be labeled as one serving."