Because it's so different than what we have here. They come up with some of the best stories sometimes and I just got hooked on it. Plus the art work can be amazing sometimes.
I'm not at 3000 yet, but I am at 662 completed and currently watching 13.
But with that said, I'm not obsessed with it, I only watch what looks interesting to me. I watch tons of American live action shows too. I'm always looking for a new show to binge watch.