Physical money has value because we have an economy. If you have a USD, you can come to the US and spend that dollar. Bitcoin doesn't have an economy, it is literally a meme. The only thing you can do with it is trade it for real money.
The value of USD is based on the US economy. The value of Bitcoin is based on people's perception of the value of Bitcoin.
The value of USD is based on the US economy. The value of Bitcoin is based on people's perception of the value of Bitcoin.