I mean it worked as money in Star Wars in the Outer Rim systems, but that was in a mature market wherein most of the "low hanging fruit" of gold deposits were already mined after rigorous exploration of the galaxy with hyperspace technology.

Even then, paper Republic dataries, which were supposedly backed by specific gold and silver denominations, became worthless after each regime change as it turned out the government was massively inflating the credit supply each time. Hence Republic "credits."

This is why Outer Rim merchants like Watto required cash only, preferably the Peggat system as minted by the Hutts, likely because they had a more credible incentive to ensure the purity of their cash currency, since they didn't have the kind of monetary privilege that credits afforded to the Galactic Republic.