One thing I like about JSON Lines is robustness to bad data - if an individual line is corrupted, you can discard it / print a warning and move on, and the pars

One thing I like about JSON Lines is robustness to bad data - if an individual line is corrupted, you can discard it / print a warning and move on, and the parser can start again at the next newline. This makes it useful for log messages / metrics, because if something crashes while emitting a log line, you can recover. If something crashes while emitting an item in a YAML list, you might corrupt the entire rest of the document. Another is that it makes streaming processing a little easier. Once you have a line, you know you can attempt to process it, and you can shard processing on newlines without a full YAML processor. Tools that work on newlines or tools that can just split on lines can handle the first level of JSON Lines output.