So many people saying the value of HIBP is the trust in Troy Hunt. But surely I'm not the only one that has used the service for years (and shared it with friends) without knowing anything about Troy Hunt...
Social credit and trust has a way of naturally propagating. Trust, beliefs, even world views are more often "caught" than deliberately and carefully chosen -- to the detriment of many. All it takes is a few liars with the appearance of trustworthiness to spread false beliefs very widely.
Note, my comment is not about Troy. Security-wise, I think the trust he carries is well-deserved.