Question What is the purpose of BakeSystem?

It seems that I can't create Entity in BakeSystem.
I want to bake all the configs of my game into dynamic buffers, and I write a BakeSystem like this:

Code (CSharp):

1. [WorldSystemFilter(WorldSystemFilterFlags.BakingSystem)]
2. public partial class ConfigBakeSystem : SystemBase
3. {
4.     protected override void OnUpdate()
5.     {
6.         var guids = AssetDatabase.FindAssets("t:ScriptableObject", new string[] {"Assets/Game/Res/Config"});
7.         foreach (var guid in guids)
8.         {
9.             var path = AssetDatabase.GUIDToAssetPath(guid);
10.             var asset = AssetDatabase.LoadAssetAtPath<ScriptableObject>(path);
11.             var type = asset.GetType();
12.             var valuesField = type.GetField("Values");
13.             var itemType = valuesField.FieldType.GenericTypeArguments[0];
14.  
15.             var query = GetEntityQuery(ComponentType.ReadOnly(itemType));
16.             if (!query.IsEmpty) EntityManager.DestroyEntity(query);
17.            
18.             var method = EntityManager.GetType().GetMethod("CreateSingletonBuffer");
19.             method = method.MakeGenericMethod(itemType);
20.             method.Invoke(EntityManager, new object[] { new FixedString64Bytes(type.Name) });
21.            
22.         }
23.     }
24. }

And conf struct looks like:

Code (CSharp):

1. [Serializable]
2. public partial struct BattleItemConf : IBufferElementData, IQueryTypeParameter
3. {
4.     public int id;
5.     public FixedString32Bytes itemName;
6. }
7.  
8. [Serializable]
9. [CreateAssetMenu(menuName="ExcelObject/BattleItemConf")]
10. public class BattleItemConfs : ScriptableObject
11. {  
12.    public List<BattleItemConf> Values = new List<BattleItemConf>();
13. }

OnUpdate

is called in edit mode. But Entities are not shown when I hit Play.
If I can't create Entity by

BakeSystem

, what is the purpose of

BakeSystem

?