Almost everyone seem to know someone that they can trust, I pity you guys because it's like you are all living in a different world, you don't listen to news and things happening around the world atleast?
Have you ever heard the term "enemy under the covers"? It's a friend who appears kind but whose heart is full of betrayal. I always group my friends into several categories, there are friends who can be invited into the room, there are friends who can only be invited to the living room and there are also friends who when they come to the house are told to just wait outside.
A friend's true character will be evident when dealing with something valuable, like money, for example. Therefore, caution is essential when entrusting something valuable to a friend. I personally prefer to play it safe and not be too open about my assets. It's better to use a P2P exchange without involving a third party than to buy Bitcoin from a friend. That would be like giving them information about my asset ownership, which I don't want to happen for security reasons.
What you say is true. Basically, we can't know what will happen, what people are thinking, or what is in their hearts, so we need to be vigilant about people and all the possibilities. In fact, we often hear of cases of betrayal from those closest, including family, close friends, close siblings, and even the relationship between children and parents. Therefore, we must be able to read a person's character, perhaps from their common habits, or we can conduct various tests on them. Personally, I often test those closest to me, usually with financial matters. I even often test a (well-known and trusted) cryptocurrency exchanger (personal) by trying to sell some of my crypto to him, then selling all of it. It might seem a bit strange, but I believe that just because someone has the trust of many people doesn't mean they can still be trusted later. I hope you understand what I mean.