Android took a big step in this direction in Oreo, with a built-in central manager of the permission and notification settings of every app on the system :)
Android 7 has that too, under the "permissions" setting for apps. It's a "I don't want any notification" or "I want all of them". Are those settings in oreo better?
Yes in Oreo every notification belongs to a named "channel" and you can customize by channel. So for example saying yes to new messages and no to promotions.