I stumbled onto some comments about Kagi angling to become an AI-first search engine that actually brags about putting you in a filter bubble. From Kagi's manifesto:

In the future, instead of everyone sharing the same search engine, you’ll have your completely individual, personalized Mike or Julia or Jarvis - the AI. Instead of being scared to share information with it, you will volunteer your data, knowing its incentives align with yours.

One YouTube video suggests a grim future: "Everybody has a feed uniquely tailored to them. Nobody talks about their favorite YouTubers anymore, because everybody watches different content farms. All the real creators quit a long time ago."

Food for thought. I don't like the idea of these filter bubbles.

ETA: I didn't realize it at the time but they also promise data collection for

• Political echo chambers: "But there will also be search companions with different abilities... You could customize an AI to be conservative or liberal"
• Corporate brand loyalty: "Ask it for a good coffee maker, and it’ll recommend choices within your budget from your favorite brands"

If you're looking for an open source search engine that's building its own data set, one exists (and it's totally open source and free).

https://stract.com/

If you're looking for something that collates other engines' contents, SearXNG is also open source and free.

https://searx.space

Kagi isn't really unique in any way here; their most unique quality appears to be linking your searches to an account, requesting money, and promising not to sell your data at a later date.