I find a simple analogy for schemaless in the OO world as well - an object without a class definition (for example a dynamic/anonymous object) and/or an interface has unknown properties and methods and is thus of highly limited use.

Just like a table without a schema... because after all, it's still likely objects all the way down.

There is no such thing as working without a "schema", because software simply can't function without data and corresponding metadata to describe it.