It breaks websites.
The idea is good, however it seems like it plainly hides the cookie warnings instead of accepting them.
This results in websites that are unusable. You click elements that don't react, you try to scroll but it won't work, etc. You refresh maybe thinking maybe something didn't load correctly, but nothing you do will fix the website, but disabling this addon and accepting the cookie notification.
It caused great frustration initially when I had no idea why can't use a website.
Turns out I didn't even have the latest version because for some reason the minimum version is now 57. So in browser updates won't work on v56 that I use.
Now I reported them.