Books

I am reading 4 books simultaneously - this is mostly because none of them mange to capture my full attention and I am having a hard time finishing them. Why is it that so many writers pour out 500+ pages books that just cant be worth more than 150-200 pages? It is something I have been noticing a lot in movies lately, that there are produces plenty picture, sound and sometimes acting perfect movies, but with very little story; little meat on the bone - so that it becomes boring and I am wondering afterwards - what did I actually see? What is the point? This also applies to some of these books, very well written, a lot of time on details, but why is it that when I have read 150 pages, the story has barley started?

If a book is going to be more than 150 pages, it needs to be worth it. It needs to be breathtaking. Please how am I going to get the power to finish these long books?