The BRICs currency will eventually be backed by gold and other commodities. Russia has a huge amount of oil, gas and strategic metals to back the ruble. The US dollar is backed by the faith and credit of the US government but with $37 trillion in debt that is increasing by leaps and bounds every year you’d have to be a fool to trust it.
It's always been the case with Russia. Rich in natural resources. But it doesn't mean that they'll attract investors. If it wasn't for the war, we'll have to deal with corruption. Other BRICS countries are similar. Brazil. China. India.
Anyone can invest in the U.S. We have an open and vibrant economy.