Do you get 1000 requests a day for your birthday or an invite to (something)ville? Rather than asking all your friends to stop sending them, just block the app. It’s easier than you think.
What you do is click on the notification and “show all”. This shows a full list of all your notifications (messages, app requests, everything).
Click on Change app settings.
Then in this window select “Never”.
That’s it! You can block all these apps and minimize your notifications to ones you actually care about. It’s far easier than asking your friends to stop it.
Hope this helps!