What you're describing isn't really that simple. Let's say you only take the top 200 to 500 sites, for example. For one, these top 200 to 500 are always changi

What you're describing isn't really that simple. Let's say you only take the top 200 to 500 sites, for example. For one, these top 200 to 500 are always changing. Suppose you keep them static. The sort of things like "spam", "fake news" and so forth are highly opinionated categories. Even if you know objectively that a site is spam, it's possible that it contains the information the user is looking for. Ultimately it would devolve to full curation, which has been tried and doesn't really work to the extent necessary to justify its own existence.