I agree that people don't change! a few ones DO change, like examples in this forum but those are the rare ones who have introspection, willpower, etc.
Our actions and decisions are 80-90% subconscious, I suggest looking for a therapist that works on the subconscious part of our minds.... often we hold beliefs there that guide our lives and as soon as those are challenged, questioned, removed, replaced.. things get clearer for us
Also the question is not about other people but about our own life and what we can do about it... that's the only thing we can control! others are who they are.
Hugs