They cited an increased interest for multiplayer and lack of time spent by the playerbase on the campaign mode as reasons why they shifted their focus. Black Ops 4 utilizes Blizzard's Battle platform for the Windows version instead of Steam, the first game in the series to do so.
The easiest way to block a website on Chrome is by downloading a website blocker extension. These extensions let you block specific websites on your device. It's also possible to block a site using a Google Admin Account, by adding parental controls to a child's Microsoft account, or via your Wi-Fi router.