Competition is free if you don't care about your privacy or your personal data. Many don't, sure, but it seems enough do care such that Kagi has continued to grow and improve over time. A tall order for what? They already have plenty of paying customers and it's a self-sustaining business already. What more do you want?
To be clear, I don't think Kagi will be next google. But I do think they have a chance to survive if they don't ruthlessly over extend their scope.