Why is clearing karma important for twin flame union?

Why is clearing karma important for twin flame union? Clearing karma feels awful. I feel like I can no longer relate to the outside world. And I no longer like music. And science, as I have found a more fundamental reality in soul connections. I can come up with some answers on my own, including the fact that karma would keep us separate energetically and physically (in the sense that we would always be repelling each other because maybe whatever we are engaging in was acquired from programming and maybe our twin flame cannot relate to that). What do you think? Why is clearing karma so important for union?

Also, a related question: why is it important to merge on a soul level? what's the point? What's the gain from it? It feels weird. I almost rather be pining for my twin flame.