This is a great question but there are the obvious one like violence, anger and abuse and of course there are just some people who aren’t cut out for it because they don’t have a handle on their emotions. There are certainly valid reasons for divorce, but I feel like, in most cases, its generally one person not making their needs felt and known, not willing to open about themselves entirely, and blowing the entire thing up because they think someone else will be able to “find them” for who they believe they are without they themselves putting in the hard work of finding themselves.