On: What is wrong with TOML? (2019)

[Ygg2]

Ironically? Fact it's a superset means it has more states and can't be as optimized as JSON.

To compound the misery YAML is whitespace indented with some extra bonkers rules. So even your JSON subset in YAML needs to obey it.

Mix of flow and block makes both modes worse. However it also makes a lot of sense.