Too bad the gold supply algorithm doesn't have a difficulty adjustment. When future fusion reactors print gold as a by-product of energy the gold supply will increase. The Bitcoin supply won't even if they try to use that energy to mine it.
The most creative part of Satoshi's invention was arguably the addition of the difficulty adjustment to ensure that the Bitcoin supply schedule would stay on track even in the face of changing mining hashrate due to high Bitcoin demand or an abundance of energy. It's a mechanism that sets Bitcoin apart from most other supply/demand systems.
Obviously the production of gold from fusion at scale is nowhere near reality (and the produced gold will be radioactive for 14 years), but it's an interesting thought experiment nonetheless.
