Github's notification system seems to be based on Gmail's design and as such has all the same problems that HEY solved. It even has a problem of not differentiating Work stuff form Non-Work stuff.
It also relies on email as it's notification mechanism which means in an organization that's group chat first, it's not likely they will ever see them. Plus they are spammy, letting you know of every PR change rather than stuff that directly relates to you.
As such, despite providing views Github's navigation is so complex that people will never know what's happening:
