The question, "Whether it is better to be a girlfriend or a wife" is undoubtedly a debatable topic.
And, the answer will definitely vary from person to person. But, I feel that every role has some unique traits attached to it. I shall discuss my views on the topic here.
A girl, when plays the role of a wife needs to be aware of the families of her husband and her own as well. She gets into a lot of responsibilities. And, many a time the responsibilities become so much that the bonding between the husband and wife start diminishing.
This is because, the girl hardly finds time from her schedule for her husband. And, this often leads to a lot of miscommunication and misunderstandings. Also, once a girl is married to a guy and becomes his wife, she starts taking the guy for grated and vice versa.
This results in expectations being not met and consequently, the harmony of the relationship gets disturbed.
However, when a girl plays the role of a girlfriend only, the spark between the guy and the girl always remains. The love and the romance never die. Both of them don't share any obligations, bindings and family responsibilities.
So, they get the time to spend some quality moment with each other and enjoy each others company. And, most importantly, nobody takes each other for granted.
Thus, personally I feel, it's better to be a girlfriend than to be a wife, if you're not yet ready for it or your relationship isn't that matured enough to take up the challenges of a married life.