So that they don't use your information in a malicious way
How to Install Extension on Google Chrome (Updated) | Add Extension on Google Chrome
Browser extensions can enhance your browsing experience, block intrusive ads, or add new functionality to your daily browsing experience. There are thousands of browser extensions and extension developers, so it’s wise to be careful about the extensions you use.
When you install an extension, you give the extension permission to use certain data. It is therefore wise to check whether browser extensions are safe and to only install safe extensions. This way you can be sure that they do not use your data in a harmful way.
Fortunately, checking the security of a browser extension can be easier than installing a program on your computer. This is because every browser extension lists all the permissions it requests before it is installed.
