Friendships end and evolve. That's life. The reason for friends is to have someone to talk to, which as humans we need that interaction. Trust is easily broken these days, as everyone appears to be out for number one, however to give up on your friends, would be ly give up on life.
As for the other friend, you don't know what they are going through ATM. Have some patience and I'm sure the answers you seek will be yours soon.