In the case of the USA, I see that it is 0%.
Yes. That is true as of 2020. Since keeping only the 10% makes the supply 10 times greater, imagine what happens when they keep no reserves. This is when the “∞/21M” meme/joke became famous. The infinity symbol indicates the current money supply.
Indeed, since there's no limit in the currency inflation, you ought to be protected from a safe haven asset, otherwise you'll be pulled to poverty one way or another. Whether that asset is gold, Bitcoin, stocks etc. Although, I think that based on what's waiting us, Bitcoin is the best choice.
What I wonder is what comes next? They have convinced the whole world to use monopoly money which they can create whenever they want, but they should know such model is not sustainable and sooner or later will collapse, so what is the next step they have planned after the collapse of the current system comes? Or do they really believe that a system that exploits the vast majority of the population of the world can continue uninterrupted?