Some observations from marriages that I’ve seen.
The more equality between the man and wife, the better chance of staying together and being successful. When they have arguments, part of the time one of them wins, part of the time the other one wins.
Compare this to a dominant/submissive relationship. If either one dominates the relationship — they get their way all the time, their opinion is the one that counts, and they tell the other one what to do and when to do it; then trouble usually follows. A person will put up with this because they lack confidence, they feel overwhelmed by the other person, they feel that the other person is smarter so they give in to them. Watch out. Trouble is coming. Sometimes it takes a long time to surface. The person that gets their way feels like everything is good. They are surprised when the other person leaves, or has an affair. The person who is submissive becomes resentful. Over time they mentally bail out of the relationship, and then finally take action.
Sometimes the age difference is a problem. Usually it isn’t the age as much as the relationship takes on teacher/learner roles. If the older person has more experience, they can be in the role of teacher at first. Eventually, this evens out where they can each learn from the other person. If one of them wants to hang on to this type of role, it can become an issue.
The most common thing I’ve seen is that people lose interest in a relationship where they have all the control, or they don’t have any control.
Try for balance.