Why are the structures in Mcreator - not who they pretend to be?

After analyzing the data about the structures in Mcreator, I came to the conclusion that they are not too similar to them... This is most likely a "Feature". I ask the developers to make real structures with the placement of mobs and extras in them. structures! The source code of the structures is again Feature code should be similar to this:

{
  "type": "minecraft:jigsaw",
  "biomes": "minecraft:plains",
  "step": "surface_structures",
  "spawn_overrides": {
    "monster": {
      "bounding_box": "piece",
      "spawns": [
        {
          "type": "minecraft:blaze",
          "weight": 10,
          "minCount": 2,
          "maxCount": 8
        }
      ]
    }
  },
  "start_pool": "NAME_STRUCTURE",
  "size": 4,
  "terrain_adaptation": "beard_box",
  "start_height": {
    "absolute": 0
  },
  "project_start_to_heightmap": "WORLD_SURFACE_WG",
  "max_distance_from_center": 80,
  "use_expansion_hack": true
}