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.
I'm pretty sure it would require some major rewriting to make it opt-in. Plus they probably want the better experience for the majority of people who don't care. I wouldn't be so quick to draw conclusions
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.
Brave honestly gets way too much hate tbh. I don't use it, but like they are tame compared to most tech companies, including google and micrsoft, both of which kagi also sources from. Makes no sense
Vlad is the founder of Kagi so you might want to focus on his replies.
There is further discussion in the Discord, which is not publicly-readable. I believe the "if we got Brave access for free" question was simply to get to the heart of users' complaints — whether they are purely financial or something deeper.