From this link:
"Netflix’s human curation takes a different approach than AI curation, in which the categorization of content is narrower. According to TechCrunch, titles in Netflix Collections are curated by specialists based on “genre, tone, story line and character traits.”
AI has worked well for the company in content curation before. However, it hasn’t been able to refine content suggestions to subcategories such as theme. Machines are able to crunch large data sets to come up with hundreds of suggestions, but the lack of a human touch leads to the inaccurate personalization of content recommendations. This is the gap the human-led categorization aims to fill."