The US voltage is 110V, and China is 220V. Which is better?

Friends who like to travel abroad will find some problems around the world. For example, use a power supply.
For the voltage, the United States is 110V, Japan is 100V, China is 220V, Asia, Middle East and Europe are 220-240V, and South America is 110/220V. Do you know why?
First, let's start with the history of power development. More than 100 years ago, Edison discovered through repeated experiments that the bulb worked most stable at 110V. Therefore, the standard is accepted by the United States. Later, another genius Tesla found that 220V AC was also very stable. In addition, the 220V loss during transmission is less than 100V. Therefore, the standard has been accepted by European countries.
Second, in the past, the Northeast and Shanghai used 110V. Later, we used the European standard 220V voltage. Due to China's vast territory, it needs to transmit electricity over long distances. From an economic point of view, 220V is also more suitable for China. This raises a question, which one is more suitable for 220V and 110V?
In fact, it doesn't matter which one is better. In the United States, fire protection is more important because it uses 110V. In China, the focus is on preventing electric shocks. However, do not think that 110V will not harm the human body. The human body safety voltage cannot exceed 36V, and 110V is also fatal. Therefore, the problem is relatively speaking. If you are promoting 220V in the US now, you will need to spend a lot of manpower and resources. Similarly, it is unrealistic to replace 110V voltage in China.
The best way is to bring a safe, high-quality conversion plug, prepare the purpose of the conversion plug, such as the British standard conversion plug; or use a universal multi-function plug adaptor, such as the 901 series global adaptors, you can rest easy.