I doubt it has anything to do with company size. Most likely it's due to what drives their products. In the case of Google, overall it's how many ads they sell,

I doubt it has anything to do with company size. Most likely it's due to what drives their products. In the case of Google, overall it's how many ads they sell, and if improving search quality doesn't lead to more ads, then there is little incentive to do it. For Kagi, they get revenue from customers paying for quality, so there is direct incentive to produce high quality search results.