>> This is a lot like schemaless databases. The flexibility of not having to fully specify the full schema does not mean that you don't benefit from specifying parts of it? Indeed, if you are indexing things, you have to specify those parts. But it is hard to argue with a straight face that schemaless tools don't have some strong benefits.
Basically when you use a hash / JavaScript-style object rather than a fixed struct definition for your data (which amounts to a schema- less database in aggregate)
Easy addition of new properties
Co-existence of different versions of objects (newer objects will typically have more properties)
Introspection of properties and validation rules / reflection
This is very similar to what Rich Hickey argued in "Simplicity Matters": https://youtu.be/rI8tNMsozo0?si=xTkpsLYTYh0jA5lB
Basically when you use a hash / JavaScript-style object rather than a fixed struct definition for your data (which amounts to a schema- less database in aggregate)