I’ve either heard or read that according to (research?) relationships are more likely to be successful if the the couple has more similarities…especially regarding major aspects (education, religion, etc).
Being opposite to one another in smaller things…such as preference for movies, likes/dislikes…adds some interest and spark. But extreme differences and too many of them may make things more challenging.
I wouldn’t treat the “opposites attract” saying is black or white. Because you have to factor in what those “opposite” qualities are and how many of those “opposite” qualities there are. Type and amount would make a difference, I think.
Also, I’ve noticed that opposite temperaments can sometimes be better for a relationship. For example, I know of two couples where the wives are very domineering and loud and high strung…and their husbands are more relaxed and patient. And had these women married someone who was just as domineering and headstrong as them…I doubt it would last very long.