I don’t really have any beyond telling them that they probably didn’t do the therapy right. Therapy doesn’t just magically fix your problems. It allows you to identify your problems and gives you tools to manage the things that trigger you.
Those going in to therapy expecting it to change their lives are probably going to find themselves disappointed. All a therapist does is listen to you. If you’re not willing to dig deep inside in order to find real things to tell them, they can’t help you. It hurts. It really hurts. Most people avoid that hurt for their entire lives.