It's unfortunate that with all the immense value that search engines provide the idea of paying a small monthly or annual fee to use a search engine is incomprehensible for most people.
For the price Kagi asks, I could buy 2 weeks worth of groceries.
A small monthly fee could mean a lot of money in the developing countries, plus there are countries where most people don't have access to international banking system. Such a system only makes access to information for a lot of people almost impossible.
A small fee to a SV resident is a larger fee to most of the people in the rest of the US/EU is a prohibitive fee to many others.