I have no authority on this subject except 68 years of living, but I’ll tell you what I think.
Only rarely do people hurt you intentionally. Most often it’s carelessness or thoughtlessness and our hurt stems from us, not them. We allow ourselves to be hurt and conveniently disregard the times we hurt someone else through our carelessness or thoughtfullessness.
Being hurt by a friend happens to most of us now and again. We can either blow off the friendship or do what real friends do - forgive and get on with it.
If it happens repeatedly, you are either choosing the wrong friends or have unrealistic ideas about what friendship is. I have only a few friends although I have a lot of acquaintances I like and whose company I enjoy. But even true friends can’t always put their life on hold for me.
Sometimes a friend can’t come to you in a crisis because they have their own crisis, or they have to pick up the kids or they have the flu.