My two cents:
If there is no romantic feeling or intent between a man and a woman, then it is just a friendship. That is possible and friendships are valuable interactions in our lives, but they are not romances.
If there is only a romantic attraction, but no friendship, then it is not a solid relationship IMHO. If you only like to be around the person because you are attracted to them physically, and you like how you feel around them, and everything is about roses and gifts and social outings but you don’t really care about them as a whole person, or you don’t have very much in common, then it is a shaky relationship. As soon as something difficult happens in one person’s life (such as an illness, an accident, a job loss, a death in the family) the difficulty becomes an annoyance that interferes with the enjoyment that comes from socializing. That is the superficiality of romance-only interactions. It is all about the romantic feeling and not about the human beings in the relationship.
True love is friendship caught afire. A lasting romantic relationship has a solid foundation of shared values and beliefs, and at least some shared background or common interests (such as places lived or travelled, education, hobbies, life goals and aspirations, and so on). Does the friendship come first or do the romance and friendship happen together? Who knows. Regardless, on some level, a marriage requires a husband and wife to be best friends, with all that entails, including having each others’ back and sticking together through thick and thin.