One great thing you can do with gold without the rest of society is paint. A little gold leaf goes a long way. I think religious icons will be very popular in event of societal collapse. Or you can add a little gold leaf to the pages of your books to add some holiness to the message.

Of course, signalling your importance and status is also necessary in primitive society, and wearing a little gold does the trick.

EDIT oh found another cool one, "Gold, with its malleability and incorruptibility, has also been used in dental work for over 3000 years. The Etruscans in the 7th century BCE used gold wire to fix in place substitute animal teeth."

https://www.ancient.eu/gold/