Yeah, very much this. Not to mention, if you want to serialize Point, then you have to know what its internals look like and what they mean. There is no data

Yeah, very much this. Not to mention, if you want to serialize Point, then you have to know what its internals look like and what they mean. There is no data abstraction. [Okay, so when you serialize Point, you can also serialize all code that will ever do anything with point. However, we generally don't do this (partially because of security issues). But it doesn't really help that much because whatever the serialized code produces when run has to be some datatype where do understand the semantic meanings behind its internals.]