No stop sign so...
I'm on the other side of the coin as a betrayed spouse and I remember the "I wish" stage well. I went through it. "I wish I could go back in time...." "I wish I would have seen the signs of what he was doing and stopped it sooner before 3 years had passed...."
It's helpful to move through this stage by reminding yourself that all the wishing in the world won't undo the damage that's been done. This stage just keeps you stuck.
What's left? Move forward.
It can be difficult for a betrayed spouse to not lose their mind when a wayward says, "I wish I would have known how hurtful these choices were" or "I wish someone had told me...."
For someone who has also faced difficulties in life and in marriage and has not chosen to cheat because the destructiveness of that choice seems obvious if one has a modicum of empathy and the ability to understand longterm consequences of decisions, it's actually terrifying to hear the person you literally trusted MOST in the world needed specific instruction on the topic of betrayal. To betrayed people, it can feel a bit like, "I don't really need to tell you not to run with scissors or poke someone else with a fork, right?" The potential for harm seems obvious.
So, moving forward looks like this for a wayward who wishes to become a safe partner:
How do I develop more empathetic thinking and actions? How does this become a regular part of how I live my life?
How do I learn to tell the truth to myself (and others) and not avoid, or compartmentalize, or justify destructive thinking or actions?
How do I move beyond guilt and shame to true growth?
How do I live authentically?
How can I show selflessness and care to those I say I love?
I do appreciate your desire to save other couples from this painful road, however. I feel the same and have had more conversations about the importance of communication in marriage with young couples since I have walked this awful road myself.