I think it’s great that you have found things that work for you and your spouse. I also don’t think those things will work for everybody all of the time.
Do you know what? I got married and we said those words out loud too, that divorce was not an option, and would never be an option for us. But things change. My marriage became abusive and my husband manipulated and emotionally neglected me. We tried to make things work for over 2 years of serious depression and struggling before I started to understand how much mistreatment I was suffering.
We both saw therapists. We went to pre-marriage counseling. We went to a Gottman seminar workshop. We talked. We went to therapy together. We talked more. We tried different things. We changed our routines. None of it was going to solve our problem.
I think going into marriage with the idea that hard work is required is good. But I also think there can be a danger in telling people to just focus on making it work. Sometimes, it is not the right choice to stay. I have never looked at marriage as something that was going to magically work on its own.