Notifications are the most immediate tool for an app (that is not Facebook, Snap etc) to engage with its users. And as you put wonderfully, it’s a tool that’s abused to the full extent because apps have no idea who the user is and what he/she are doing.

Regarding your Long-Term Solution, I work for Neura and our company works towards exactly that. A developer using our tools can notify her end-users exactly when the notification is relevant (according to location, personal state, context and other variables)