Some general websites such as Reddit or Youtube can be used both productively and as a distraction, especially when Reddit posts appear in search engine results as an answer to some problem or question.
Having the ability to block or allow website access at the sub-directory level or perhaps based on the site you're navigating from (previous URL filter to allow google search -> Reddit but not Reddit home -> subreddit) would provide more flexibility to be able to access those sites in a non-distraction context.