In everyone's life, there's enough negative feedback. From parents, employers, loved ones, and completely unrelated people. One casual word can uproot belief in oneself, in people, and in relationships.
It's important for people to know about their strengths; sometimes, they are unaware, forget, or doubt them. They are not aware that they are beautiful, funny, smart, and talented. They are constantly in confusion, crushed by criticism from all sides.
This is not about reciprocity, flattery, or sycophancy. It's about letting dear people know that they are valued. Tell them that they are simply awesome.