There are no more completely original ideas. There are only partially original ideas.
It’s important to recognize what part you are taking and what part you are inventing.
A new book is not original. The book part. The cover and pages is a stolen idea. But inside the book, it could be a new author or new content. That part is original.
So put aside the fact your idea has to be completely original in order to work. Because the market doesn’t need completely original ideas. In fact, chances are if it’s never been done before you probably won’t find a market for it. What we need is your twist, your innovation, your invention on what has already been done.
There is no need to reinvent the wheel. Just make it better.