bitcoin is not backed by any assets....The majority of currencies used in the global economy do not have any backing. By definition, a fiat currency is a currency without backing, and this is what every major economy in the world uses to conduct daily transactions inlcuding USD
Exactly the US dollar ain't backed by anything and was decoupled from gold back in the 70s thanks to Nixon Administration. Money in most countries including the US isn't backed by anything and is printed from thin air.
The only difference is that 1st world countries money is basically backed by their power, influence and military. That why their money isn't volatile. But developing countries don't have this power and influence so that is why their money is highly volatile and why inflation runs crazy in those countries. That is one reason so many people in Latin countries use Bitcoin because it stores actual monetary value better their their countries dollar which loses value due to extreme inflation. Plus its much cheaper to send bitcoin back and forth to family members than western union or other wire services.