Comparing Harry Potter to Power Rangers... blech.
Voldemort is the main villain of the series. Think of all 7 books are one big epic story. You can't just have each new book have a new villain. It would ruin the continuity of the series, and each Harry Potter book adds on more and more information to the continuity.
Alright, here's another comparison. What if The Bride in Kill Bill had stopped going after Bill in Volume 1? Maybe she thought it would be too hard, and gave up. And then in Volume 2 it's about her trying to get a job at a supermarket, or something like that. And the villain could be her new boss.
It's stupid.
Voldemort is the main villain of the series. Think of all 7 books are one big epic story. You can't just have each new book have a new villain. It would ruin the continuity of the series, and each Harry Potter book adds on more and more information to the continuity.
Alright, here's another comparison. What if The Bride in Kill Bill had stopped going after Bill in Volume 1? Maybe she thought it would be too hard, and gave up. And then in Volume 2 it's about her trying to get a job at a supermarket, or something like that. And the villain could be her new boss.
It's stupid.