I can't speak for men who cheat or men in general. I can only speak for me.
While I'm a Betrayed, I can speak to the "what does it take" question. I poured a lot of shit in my marriage and didn't wake up to it and what effect it had on my wife until she read me the riot act and I realized I could lose her and my family life. I had a good hard look at myself and days later I was wracked with sobs and guilt and anxiety. That's what it took. I was (still am?) a controller, so by nature when you take control from me I become very, very scared.
Take this with some salt, as my perspective might not apply to your WH. If you do decide to lower the boom on his ass, and file for a D, BE PREPARED TO FOLLOW THROUGH. Controllers can smell weakness like a shark smells blood in the water. If you file for D, do NOT falter unless he comes to heel. Falter once, and he'll know you're faking it, and he'll be all over you.
Strength and good luck.