The content/metadata dichotomy is less relevant today. The days of managing content as big chunks of HTML are (thankfully) mostly behind us, and most content has a higher degree of structure.
And this brings us to the awkward question of whether metadata in the classic sense even exists anymore.
Here’s the definition of the prefix “meta”:
A prefix added to the name of a subject and designating another subject that analyzes the original one but at a more abstract, higher level
So, the word “metadata” literally means “data about data.” The idea was the metadata was used as a tool to organize, clarify, or filter the “main” data. This means that to say something is metadata is to tacitly admit it’s modifying some other data, which exists somewhere else.
Metadata only has meaning as a concept if it’s separate from some other data. Refer back to the document management scenario and it makes more sense because the document is “the thing” and the metadata is “the other thing.”
But what if there’s no document or big chunk of HTML? What if there’s no thing?
Put another way, what if everything is metadata? If everything is metadata, then nothing is. There is no “other.”
The truth is that with most modern CMSs, the idea of “metadata” doesn’t exist. All data is structured, and it’s lumped into the same interface.