Having a gold backed stable coin allows them to trade alts to gold and vice versa.
This is easy to do if they can claim it easily, but the problem is most of the time it is quite hard to do so. If you live in South-East Asia, how will you be able to claim that "gold" from some developer who lives in Europe? Most of the time you'll probably trade it because it's quite fast and simple, and because of that there's no real reason to actually tokenize or create a coin which is pegged to gold or any other assets. It will be just pure speculation, with limited usage. No need to buy a token to own gold, just go to your local store and buy gold, store it in your home and you're good to go.
I don't think the idea would be to hold it but I take your point. I think it's so that they can trade gold/crypto while avoiding holding fiat. They can then grow their gold amount in the idea that overtime gold will appreciate against fiat. Then whenever they see fit they can convert their gold to fiat and not only will they have increased their gold amount, that gold will have increased in fiat value.
