Yeah, it seems like the only "general solution" to this problem is to measure the number of "human work hours" that went into the production of a specific type of "content".

Content would then be labeled as "AI generated" if the "human work hours" was less than X hours (like 0.5 hours).

Whereas content would not be labelled as "AI generated" if the "human work hours" was greater than or equal to X hours (like 0.5 hours).

That would likely require sharing with YouTube not just the final work product, but rather all the iterative work product that led to the creation of the final work product (i.e., earlier drafts). When YouTube could calculate the number of "human work hours" based on the incremental creation/edit histories when analyzing all the drafts.

This is a very hard problem and unlikely to actually be solved in this way.