Not everything has to be named once and put into a hierarchy like a directory tree. Tags work well for data. A system like an LLM that understands synonyms and antonyms should be able to find and even update tags for concepts that don’t have a full set already - as long as there are a few appropriate tags on the concept to start.
In practice if you're making up tags on the fly it's not much better than untagged data. A LLM that can figure out what the tags mean can probably just infer it from the data anyway.