The Hobbit and the Heroes Journey

This week I read the classic fantasy book that is The Hobbit by J.R.R. Tolkien. When I was a kid I watched the Lord of the Rings movies many times but could never seem to make it through them without falling asleep, but I found that while reading The Hobbit, I couldn't put it down. The story feels the same but also completely different from the Lord of the Rings movies, whether it be the set up or the fact that it was coming from different mediums and while reading I could be more imaginative. I could argue that it wasn't the change of mediums because I had also tried to read the Lord of the Rings books when I was a kid and couldn't get a couple chapters in.
It's obvious with any of these stories kinds of stories, especially young adult novels, that the heroes journey practically screams in your face. It feels like J.R.R. Tolkien saw what the heroes journey and literally built his story around that idea, like he took as a rule that he had to follow to the tee. In the heroes journey it goes from the character living their normal life, in this case Bilbo living in the Shire, to the call to adventure which is literally Gandalf knocking on his door and telling him he needs to do something. Gandalf also acts as the "mentor" or character that helps him through various situations. He meets up with the dwarves (who can also be seen as mentors because Bilbo doesn't know much about the world) and they travel to the lonely mountain. They end up in various places and situations which is the challenges and temptations. He finds the ring (a literal temptation), which ends up helping him. And after everything, he just goes back home, with a new perspective on the world, but everything else is the same.