"Infatuation is the state of being completely carried away by unreasoning passion or love; addictive love. Love can be described as feeling of intense affection for another person. It is most often talked about as an emotion between two persons. Hence is also sometimes referred to as interpersonal love."
In my opinion, what Ovi feel for arjun is infatuation while what purvi and arjun feel for each other is LOVE. Based on this, I am of the view that Ovi and arjun marriage failed because they were never in love even though they tried to make it work. On the other hand, purvi and arjun even though not married and has been separated for so long still have that strong bond or emotion between them that makes their relationship so successful up until now. If purvi and arjun are to be married, I think their marriage will be very successful as they love and respect each other. they also listen and understand each other's views. Sometimes they dont even have to speak, they just sense the problem/concern.
I do hope that archana would make sure as a mother that purvi gets her love and live a happy life as she of all persons would know what true love is and how difficult it is to make a sacrifice as huge as purvi and arjun. Ovi has already made her decision to move on, then she should allow her. It makes no sense trying to bring she and arjun back together because they are in a so called marriage. It has not work and it would not work.