Two points:

• We don’t have a fixed money supply in the modern system when banks can issue debt. Not even close. I suggest you read the Bank Of England’s paper called “Money Making in the Modern Economy” which I mentioned.
• We’re talking about different things here. I’m not suggesting Gold as a trade token, I’m not even suggesting Gold as a store of value for stable times, I’m suggesting gold as a store of value against things like large economic crashes (the upcoming AI bubble crash, possibly with a Realestate bubble crash) and those times when the dominant Imperial Power in the World is being replaced by a now one (such as it seems to be the case new ones, as now with the US decaying and China rising). I’m suggesting that, purely because Gold has way less exposure to Politics and human mismanagement in general than even major currencies.

I think I failed so far at explaining myself mainly by talking too much.

My point is simple: gold and fiat currencies are roughly the same, but gold isn’t issued by anybody and isn’t managed by anybody whilst fiat currencies are, so gold is less exposed to the risks inherent to greed and corruption of those who issue and manage currencies - there’s not temptation to “issue more gold” because it’s not at all possible, there is nobody deciding “gold interest rates” because there is no such thing (to have interest you need to have more money tomorrow than you have today, as today’s loan will be repaid tomorrow plus interest and you can’t really make more gold any faster than mining it)

Gold has less exposure to Politicians and Central Banks - that’s it, that’s the important difference.

In stable times when living in mature Economies, that difference is pretty much irrelevant, in times like now it can make a huge difference which is probably why the GLDUSD exchange rate took of with the Russian invasion of Ukraine and accelerated even more with Trump’s second mandate as POTUS.