I was using biodiversity as an example. All of those other resources you list also become devalued if another, better source is discovered elsewhere, which will also cause your currency to crash.

The reason for fiat is so line can go up and the top capitalists can get more power.

Bluntly, you don’t understand economics, not even at a high school level.

Inflation is good. You want inflation. You just don’t want too much inflation. Inflation is necessary for an economy’s growth to keep pace with the population, which–in Africa–is still growing. If the population increases, but the monetary supply does not, then the money you have now becomes more valuable tomorrow. That sounds good, except that means that no one spends money. That is commonly called “deflation”, and deflationary periods almost inevitably lead to economic depressions. If an economy is experiencing deflation, that means that borrowing money is really expensive, and most businesses can’t expand or make capital improvements without credit. No one borrows money in a deflationary period, and because no one borrows money, no one can invest money. Money just sits there, not being used, because everything past the minimum necessities becomes too expensive. (Expensive as in, the money I spend now will be significantly more valuable in a very short period of time, so I’m “losing” money by spending it.)

The problem with inflation is when wages aren’t keeping up with it, or when it’s happening so fast that people can mentally track it. E.g. my favorite cereal went from $6 in 2019 to $10 now, about a 65% jump. Even if my wages have gone up 65% in the same time, that feels like I’m paying a lot more, even though it’s the same percentage of my income. (And yes, corporate profiteering, starting in 2019, has really been driving inflation. Yes, companies lied to us and just raised prices. Yes, I’m fine with tarring, feathering, and then publicly executing the executives that did that shit.)

But with fiat currency, you have a mechanism to control that: the prime interest rate. If inflation is too high, the central bank (the Federal Reserve in the US) can raise the interest rates that it charges to banks, making it more expensive for banks to borrow money, which gets passed on, and slows down credit and spending, which eventually slows down inflation. If inflation is too low, the Fed can reduce the interest rate–literally printing money–and banks will lend more, and people spend more. With careful management, and a lot of luck–and assuming you have a gov’t that is generally trusted–you can keep the currency stable. There’s absolutely no guardrails for a currency that’s linked to a specific resource though; if more of the resource is exploited, then the value of the currency decreases, regardless of whether or not that’s good for the whole country.