There’s a thought-provoking article and discussion at Intercom on "The End of Apps As We Know Them". The premise is that we will use apps directly less and less and instead interact with rich notifications or cards.
While I can see some notification-rich apps might work this way, I am less convinced that the majority of apps will end up working that way. Most apps do too much to be shoehorned into a notification style app. Also, people are more used to invoking apps via icons and I can’t see that going away. I think cards/notifications are great for end user consumption but not end user content creation. If the majority of apps were to use this paradigm then the user would become overwhelmed with notification overload.