Thanks for taking your time read. I agree, this new system gives a very scary impression.

But in reality - the extension can only access these permissions on two sites - YouTube and it's own returnyoutubedislike - on all other sites it's not even allowed to "turn on".

Personally identifiable information - RYD’s randomly generated private user ID used to count votes, not your real identity.
Browsing activity - i.e. navigating to the next video, so that the next dislikes can be shown
Website content - i.e. the like\dislike container element
Website activithy - i.e. clicking like or dislike button.

As I already said - only on YouTube. Not everywhere.