Hmm I'm not sure about the technical side of Bluesky feeds either, but they seem to be user-made (?). In my play about on Bluesky I have seen several film feeds (one uses all notes that add a 📽️ emoji to select from, and the moderate for eg).
But yeah I'm not sure about anything :)
Bluesky feeds are curated. That's why they seem to work better and have higher signal. The data gets pushed through a filter, basically.
DVMs do something similar, but instead of doing it continually, for everyone receiving the feed, you send off a request and they run the filter for you, especially. That's why it's called a "Data Vending Machine". That's more personal, but also more resource-intensive. Makes more sense to do use that tool for more complex and uncommon combinations, than "show me the feed about baking" or "show me the top ten notes on the biggest 10 relays".
