I don't think a gold standard is a viable pyramid scheme for a multiplanetary species. There's too much of it in space. You need something that is rare even after traveling for hundreds of years. A lot of wars were simply fought over resources. It's even better if your society uses the resource as money. The only thing I can imagine is using habitable planets as currency, this would require your galactic empire to have a dozen planets though because a single planet does not make a currency and the debt trap of borrowing 1 planet at 3% interest would fall apart because colonizing the next planet may take too long to pay off the interest. I.e. you need some planets to lose before you take that loan.

Edit: Great filter hypothesis to explain Fermis paradox. The pyramid scheme needed to enslave the galaxy is also powerful enough to destroy a planet before it develops space faring technology.

Just to point out obvious, you are applying a human logic to an theoretical alien species of theoretically any type of behaviour/value/technological/political angle.

Who knows what they are like and what they value.

Thank you another book/trilogy to add to the reading list.

I suggest you also add The Wandering Earth by the same author to your list, which is a collection eleven of his short fiction stories. I'd even go as far as say it's better to read it first before the trilogy.

You’re welcome! Incidentally, there’s no FTL in the story.