You have real ex gifted kid vibes.

GG is not being assigned because teachers "like" it and want to impose their taste on everyone else, it's assigned so that you can learn how to read literature. Scarlet Letter and anything Hemingway are also good for this; I "dislike" them all (except for some of their short stories!), but they're absolutely excellent for what their presence in the curriculum is designed to do. Which is, again, to teach teenagers how to read literature.

As for Julius Caesar and Romeo & Juliet - if you dislike them or think they're boring, you should just not be teaching English. Or you should read more mediocre American lit under the guidance of a high school English teacher until you learn how to appreciate them.

But as another person said, elementary school teachers don't get to choose what they teach.

Edit: a tangent. This attitude towards books really bothers me. Do you see anyone who is like "students should choose whether or not they learn algebra"? Or "geometry is so boring, let's throw it out and do more times tables"? Or "I don't like Spanish verbs, i should be able to just do more adjectives"? Would you trust a coach who didn't want to teach anyone how to pass and dribble and just focus on slam dunks? Come on. Literature is an extremely rich and rewarding field of human endeavor, and as wirh every single thing that people do, there are barriers to "getting" it. Books like Gatsby, however irritating, are necessary in order to get past that barrier. Which you don't seem to have done, OP.