Do girls date only with the intention of getting married?

I was dating a girl who was 3 years younger than me, we used to hangout during weekends, had video calls in the night, went on long drive, and had kissed was well. We both knew that we like each other so neither of us had proposed each other. But one day all of a sudden she asked me that if my parents would accept her if we get married. I said that it is quite difficult because we both are from different caste but I will somehow try to convince them.

After that I had gone to my native, there was a small gap of 2 weeks or so during which we did not meet each other but we used to talk on video call in the night. It was around one and half month since we had started dating. When I came back and met her she said that this relationship won't work out as my parents would not accept her and she is looking for someone with whom she wants to marry. In between we had a small fight in which I was not ok with her wearing short dress and posting on Instagram but we sorted out. Also she is non-veg and I am a vegetarian, but we both respected our choices still there was a small fight with this topic as well. So I am not sure what could be the reason she left, but the reason she gave is that if can't marry then why to date.