That’s an extremely effective example with paypal; I only noticed the difference after reading your footnote. I imagine it’s also quite useful as a quick means of knowing whether you’ve already signed up for a site, to save the effort of opening the extension and searching or creating a new account.
In my usage case, I have many accounts on the websites I visit most so I’m seeing a near-constant display of anywhere from 5 to 9+ when I don’t personally need it. I would definitely want the removal to be a slider option and not the only behaviour offered.