You're paraphrasing Internet follies to make yourself sound smart.
Theres nothing positive about getting cheated on, nor does it happen with the intent of doing you a favor, but to use and exploit you. It can be traumatizing to an extend you don't trust your own judgement anymore when it comes to who to trust, and can lead to paranoia and control mania later on. I don't know how a normal person can adapt this warped state of mind. Think of it in any other context, and you would agree its nonsense: "If your business partner defrauds you, he is doing you both a favor. Stop selecting bad business partners if it keeps happening." Unhinged bullshit.