Pause the technology there, let's look at an example. Let's say you buy something while traveling abroad. What if you use VND to pay when that place only accepts USD? Of course. you won't be able to buy it. The solution is that you will swipe your card and pay in USD to the merchant. After that, the card issuer will verify and deduct an amount of VND corresponding to the specified exchange rate. That's how the traditional financial model works. But isn't that the case with blockchain? You cannot use ETH to pay when the seller only accepts ETH. Simply because there is no tool to help them convert from BTC-ETH at that time. If they want to own ETH, you need to convert ETH. Blockchain was born with the desire to solve different problems. Unfortunately, they develop independently and lack inter-platform communication. This has caused inconvenience to the users mentioned above. So in summary, we can easily see that current blockchains have some disadvantages as follows: