I want to be able to easily read and understand configuration without having to pop it into a converter. The YAML I encounter in the wild is ~80% pure block style, ~20% mixed (within a single file, mostly block style with some flow style). And I just find the block style hard to read, I have to either spend significant mental effort trying to understand where the objects vs. arrays are, or I have to pop it into a converter (to either JSON or flow style) to understand. Whereas JSON/JSON5, it’s immediately clear without any mental overhead.