
The keyword here being download, implicates that you cannot use any type of Video downloaders, including Chrome extensions, on YouTube to download or save any video to your PC.

Once you start using YouTube, you agree to its terms of service which say that “ You are not allowed to access, reproduce, download, distribute, transmit, broadcast, display, sell, license, alter, modify or otherwise use any part of the Service or any Content except: (a) as expressly authorised by the Service or (b) with prior written permission from YouTube and, if applicable, the respective rights holders”. However, despite the fact that it is so popular, one cannot download YouTube videos via Chrome extensions or be it any downloader.

Reports suggest that YouTube is the second most used search engine after Google, despite the fact that it is a streaming service and not a search engine. YouTube Videos are the go-to solution for many when it comes to entertainment or educational needs, or if you want the solution to anything else.
