It's really only since the early 20th century that platinum was valued higher due to its rarity, but, perversely, the relative abundance of gold vs platinum was what made gold the historically accepted currency - it was far more practical to mint gold coins than platinum ones. Gold has retained that status, and continues to be seen as a safe haven in times of uncertainty, which we are definitely in today with BRICS wanting to establish a commodities backed (predominantly gold) reserve currency, and the US at the point where annual interest owed on debt is equal to military spending. Something is going to give, and gold is seen as the place to be when it happens. Central banks certainly see it that way, and their buying is in part what is fuelling the rise in price:
Central Banks | World Gold Council
The historical comparison of gold vs platinum also tells the story. For the 19th, and much of the first half of the 20th, centuries, when the British controlled the world reserve currency, gold was artificially pegged in order to prevent volatility. (While platinum was virtually valueless during the 19th). It then found its own level during and after WW2, as Britain lost hegemony. It achieved parity with platinum during WW2, and again during the inflationary period of the 1970s. The 2008 GFC saw the beginning of its rise above platinum, and the uncertainty caused by Covid sealed its higher position. With the Ukraine war, the now accepted use of gold as a petrocurrency, and continuing US financial uncertainty, it is expected by many to keep rising. On the other hand, platinum, having no such financial safe haven value, continues to be priced according to its demand for jewellery, electronics, and other minor uses.
Platinum Price vs Gold Price Ratio | 125 Year Chart (sdbullion.com)