It’s a shame Apple have not been as strict about spammy notifications as they have about other aspects of iOS. I realised the other day that I automatically don’t allow notifications for virtually any app, primarily because I expect it’s going to spam me. Some apps would actually be enhanced by notifications but I never allow it. The default notifications allowed for any app should be only relevant, action-based ones…
Everything else is set to off or to only notify while I’m actively using the device (banners only.)
I also only enable saving in Notification Center for things that I may want to see past notifications for.