Star Trek vs. Star Wars (and a collection of memes)

It is covered that latinum is one of the few substances that cannot be replicated, that is why Ferengi use it as currency. Gold can be replicated quite easily. They put latinum inside gold because as Jadzia once said, Ferengi got tired of counting out change with a medicine dropper.

Though for meta reasons, it is tied to gold to make it more relatable for Star Trek viewers.

Really, any non-replicate-able substance in Star Trek can be a trade good. Latinum is different, it is only valuable because it cannot be replicated. Other non-replicate-able substances can be converted to weapons, starship parts, or fuel.

Then there is stuff that cannot be replicated perfectly. It is generally believed that non-replicated food tastes better than replicated food.