After installing Google Drive on macOS, I suspected it was a bug in the program. Even though my system language is set to Traditional Chinese, Google Drive displayed Simplified Chinese. It looked really unfamiliar, so I researched it and found a fix to share with everyone.
Just open Terminal and enter the following command, then restart Google Drive, and it will switch to Traditional Chinese:
defaults write com.google.GoogleDrive AppleLanguages '("zh-TW")'