Not the parent commenter, but it really gets tough to figure out _where_ you are in a bunch of nested lists, objects, etc deep down in the yml file. When the schema gets complicated enough you start having to refer back to the documentation to understand what syntax a particular item needs (I'm looking at you, docker compose!)

One example from a larger file:

  networks:
    macvlan51:
      driver: macvlan
      driver_opts:
        parent: eth0.51
      ipam:
        config:
          - gateway: 192.168.51.1
            subnet: 192.168.51.0/24

Maybe I'm just getting older and dumber, but that hyphen under config seems completely arbitrary to me (and the necessity of it is poorly documented in the manual). This gets magnified to the extreme as your config file grows. Maybe this is a list of objects under a key? Who knows.

Edit: OK, it looks like hyphens indicate arrays in the schema but for me it feels like a guess as to which one of these to use for each particular case.