Apple's linear messaging center was best sprinkled since iOS 9 when we were able to group notifications by app. Without some sort of grouping capability, the notification history tends to be a nuisance of random alerts based only on time, making it a treasure hunt to find the desired alert. Now iOS 12 has fixed this issue and restored groupings – with improvements.
While you've had to opt-in to apps grouped by iOS 9, you do not have to enable anything in iOS 12 to get grouped notifications on your iPhone. By default, they are set to "Auto" grouping for each application-neat, organized batches that significantly disarm your messaging center and lock screen.
In This "Automatic" setting organizes content from the same app into separate groups such as two batches of message notifications for two different contacts, three different batches for three different news sources from the News app, and so on. It makes clear the overall warnings, and makes the story much more comfortable overall.