I am a happy married man. Married my wife 6 years ago, after living together for 14 years. We have two kids, 14 and 11 who enjoyed the wedding
I don't regret it. Women seem to need this celebration, and as it was a nice opportunity to bring all friends from all periods of our lives together at a nice place. It was awesome, I don't regret it.
If you have a relationship, and things are going not-so-well, it is easier to step out and look for a better partner. If you are married, you will put more effort in Fixing the actual issues, and this works. At least for me.