I don’t have a source but this is based on my membership in the Kagi Discord server. Kagi search has decided to allow people to opt out of Brave results being included in the results and may asking Brave for free API access so that they aren’t being supported. I’m still unsure about whether I’ll resubscribe to Kagi. I might give Startpage a run for a bit.
From my experience? They’re not. Results and UI are so much worse. Aside from significantly better results, the little things like keyboard shortcuts, ddg bangs + custom bangs, lowering or raising sites in results, etc.