If you have subscribed to loads of different YouTube channels, it might be a bit of a mess to go through all of your notifications. Recently, the amount of notifications have suddenly dropped significantly.
According to Engadget, Google has began muting push notifications from creators that you haven't engaged with in the last month. The idea is that if a viewer continually receives notifications about content they don't engage with, this may eventually cause the user to disable YouTube notifications entirely.
Notifications from channels you haven't engaged with in the last month will continue to be available inside the YouTube app in your inbox, which is that little bell icon in the top right. YouTube has also stated that "channels that upload infrequently will not have their notifications affected".
There is still one thing, that is a bit uncertain. Will YouTube automatically restart related push notifications, when the user decides to engage with these channels again in the future? Let's hope that they will.