How do you want to change Pi into USD, VND? Who will buy the Pi? What do they buy Pi for?
1 Pi purchase transaction
Once Pi is on the Pi floor, Pi will provide us with an e-wallet, when you sell Pi on the exchange, the money will go to your e-wallet and you will transfer money to your bank account.
In the Pi ecosystem, companies that want to advertise their brands have to pay fees in Pi. If they don't have a Pi, they have to buy it in USD on an exchange.
The intermediaries, retail sites that want to sell in the Pi ecosystem have to rent the booth and pay fees for the Pi ecosystem. In order for their sales to be guaranteed, they must have multiple Pis in their account to deposit. So they have to buy Pi on the exchange in USD.
Money speculators and financial companies buy Pi on an exchange with the price up and sell for a profit.
2 Exchanging goods using Pi
One fine day, suddenly you want to shop without salary, your wallet is out of money. But you still have an account with the Pi. Turn on Pi, go to the sales page to select the product, then order and pay with Pi. That is the Pi peer-to-peer ecosystem that Pi Network is aiming for.
You can use your Pi to pay for meals at restaurants, coffee, spa, pet beauty, etc.
Big players in the retail shopping industry are all actively participating in the Pi ecosystem. The Pi will gradually update the 3rd parties participating in the Pi ecosystem for the community to understand.