Even if the entire customer base was limited to only HN users with karma exceeding X amount there will still be thousands of searches per day in obscure niches,

Even if the entire customer base was limited to only HN users with karma exceeding X amount there will still be thousands of searches per day in obscure niches, just each one in a different niche. So I don't see how Kagi can avoid having to deliver quality search results in millions of niches. Just at a very low frequency compared to Google. Or are you suggesting to not bother with search quality past a certain lower threshold?