It’s not. It’s just easier to watch a TV show or a movie than it is to read an entire book. And if you’re not much of a reader to begin with, then, as you say, it’s no contest.
The truth is, there is almost NO TV or movie adaptation of a book or short story that is better than the written version. There are some that are more approachable, more consumable, more digestible, or even more exciting, but almost NONE are actually BETTER than the book. The main reason for this is scope.
Most TV and movie adaptations are forced to pare the work down to its most basic elements, sacrificing the breadth and depth of the written version in favor of brevity. This necessarily strips away the prose of the story, the aspects of the piece that bridge the gap between a mere synopsis, and a work of written art.
The Hobbit is one of the greatest children’s books of all time, and one of the finest pieces of imaginative fiction of the 20th century. There is no way a cartoon from 1977 is better than it. You may enjoy it more, it may have a certain nostalgic appeal for you that’s missing from the book, but have no doubt, those perceptions are yours alone, and while I won’t call them unique to you, they most certainly do not reflect the majority view.