I agree with the overall message of the article, but I don't think "serialize" is the right term here. Serialize means going from in-memory data representation

I agree with the overall message of the article, but I don't think "serialize" is the right term here. Serialize means going from in-memory data representation to a flat bytearray, which is eventually persisted. There are numerous way to perform serialization, from just memcopying the datastructures up to defining a good and extensible persistent format and converting into that. The compatibility and extensibility issues are mostly coming up from the first approach. And can often be avoided by utilizing a more flexible persistent format, which can be anything from a total domain-specific format up to json, xml, protobuf, etc.