I read some ancient American sci-fi from the 30s and 40s, and you'd be amazed at what ideas they cover.
I apologize for not being able to remember the names of any of them right now, but one story springs to mind rather easily.
A guy ends up going to the future (don't worry about how) from the when the author wrote the story. It's about the characters experiences in the imagined future.
In it, everyone was rather well off as your income was essentially a production dividend from the government. As one character put it, the populace is so productive the government is always looking for new and expensive projects to spend money on, they have too much and have to use it.
I know some people will freak out over that for various reason, but the idea is sound, even if it would never work with humans the way they are, just like any utopian ideal. However, one of the points on it is based on economics. Saving or hoarding money, especially by the government, just locks up potential resources for no good reason. If it is spent, it is in circulation and helps the entire economy. Anyone who has taken sufficient economics knows that the value of stashed cash is virtually zero to an economy, and can easily become a negative, while money in circulation is powerful.
Honestly, other than Liu Cixin being heavily influenced by his countrys political propaganda (all countries have that to varying degrees) I don't really seen any new ideas in his works, just variations. Still, I wish him success in his writing career.
If you want to read some other stuff that is eerily similar to his on occasion, hit up some of the old Soviet sci-fi.