Speaking from my own experience, I’m either on looking for right now or just wasting time. If I’m looking for right now I’m going to be very active in the conversation, but if I’m just on to waste time I’ll initiate conversations and then drop off cause I was more just curious to see if the person would chat back. It’s like a validation thing. Obviously this sucks for the person who was expecting an actual convo or continuation. Well anyway there’s an explanation for you. It’s not what you said, it’s most likely that the person wasn’t invested from the start and they didn’t continue the convo cause they were at work, busy, wasting everyone’s time etc.. maybe they got more validation from knowing you would even respond than fighting for a connection