while heavy on rags-to-riches fantasy とはどういう意味ですか?

質問を翻訳

So rags-to-riches is a story format where someone goes from poor to rich and that’s one of the main story arcs. Another example of a story format like this is “the hero’s journey” which is more well known.

So a “rags-to-riches fantasy” is like the stereotype that goes with this story format.

And if a show is “heavy on rags-to-riches fantasy” it means that it relies heavily on this stereotype/type of story, instead of developing a more interesting/original story/plot.