Yeap, I do not like most stories based on real life. Humans are different but human societies are usually the same.
I disagree.
Humans are different, ergo human societies are different. Consider Venice. No land (built on marshes) - no land nobility. That alone drives them into a radically different direction. They become fishermen, then traders. A relationship between a captain (a merchant prince) and his men is very different than that between a landowner and his peasants. Seamen need to be capable and armed. Peasants - meek and obedient. A trader needs to know his numbers and laws of different lands (meaning he has to be literate and skilled enough to understand, interpret, and argue contracts), which gives them an unparalleled advantage, leading to the creation of a trading empire powerful enough to demand that the Crusaders attack Constantinople, a Christian city, before proceeding to the Holy Land. Their threats were more powerful than the Pope's at those time.
That's just one example out of many.
When you move your story to the space then this allow you to introduce something new what reader do not see around himself.
I feel that fiction, be it fantasy or sci-fi, has to be realistic first.
But if you focus your story on aspects which reader already have seen then you need to make this things really good. Author cannot make story interesting because "it's sci-fi".
That I agree with.
I think I should try your Age of Decadence. Maybe there are something new or realization is on different level.
Try the demo first. The game is very different but not for everyone.