Given Kagi's abysmal adoption rates, it's clear that good search isn't worth it for most people.
These days my default assumption is that any SAAS product will get worse and more expensive over time, so it has to be pretty good to justify reworking my online habits around, given that I don't know how long I'll keep using it. Hopefully Kagi will be the exception to that rule, but I wouldn't bet on it.
But that’s also the answer on preference. Google is good enough for most people. For everyone else, there can be a paid premium layer. Similar to news, this might be the equilibrium, not an anomaly.
I relayed this story to a friend who suggested I try Kagi. It was on the first page on my first attempt. I was also able to use it to find a different article I was sure I read even longer ago, that I didn't have as clear memory of.