Network layer blocking is almost never in the interest of the end user. It's typically used to block users from accessing sites they want to visit, like The Pirate Bay, or recently Russian Times and Sputnik News.
End users who want to protect themselves can easily install blacklists on their end. All major browsers support something like Google Safe Browsing out of the box, and these blacklists are more likely to be kept up-to-date than those of the average ISP.
Either it's easy to block sites or it isn't. There's no world in which it's easier for you to block scam sites than it is for others to block vital resources and information.
ECH makes it hard to block known scam sites at the network layer, for example.