For me (a multi-year paying subscriber), one of the many indications of Kagi's difference is a) that it has a changelog and b) that the changelog shows so much granular work.
They may never become huge (they are explicitly building their business model such that it doesn't require growth to succeed), but if they ever do, they will be able to maintain their mission and goals, but they almost certainly won't be able to maintain that small, human feel.