YAML:

  - - "hello"
YAML expanded:

  -
    - "hello"
JSON (typical formatting):

  [
    [
      "hello"
    ]
  ]
And EDN for good measure:

  [["hello"]]
I know which one I prefer :) Silly example perhaps, but once you have X lists nested in Y lists, it does become a lot easier to see why some prefer a bit more visually hierarchically stronger syntaxes

I still prefer ini files for configuration. Easier to grep and sed.

You can get a bit more if you use TOML over INI... it's similar at a baseline, but still a bit more rich for advanced configuration than INI is.

They work wonderfully until you need to do anything more advanced than a key-value store.

My belief is that anything that requires more than that are hiding the fact that what they truly need is a DSL. Instead they force you to write AST (ansible, github actions, docker compose,…)