None of my INFJ friends trust me

I am close friends with some infjs and I am also extremely trustworthy. When they don't know what is happening, even in their own life, I can display every detail of their own life right to them. We have a lot of time together and a lot of that which infjs call Fun. Yet, they do not trust me with their lives. They fully trust no one. I ask them why and they have no answer. I show them every reason they have for thinking such a thing, and how it is wrong, and they still choose to not trust. I am not sad about it but it is such a missed opportunity for them. I even show them that if I had malicious intent, I could've obliterated their psyche already, and also how to defend from that properly. It is especially weird because they trust me with things that I could easily use to ruin their life, but not other things that I can't even have any influence in.