My apologies in advance for a very long post.
After reading all of the posts concerning this topic, I’d like to offer a few comments that might provide a different perspective.
When I first noticed the “Hidden” group in my App Library, I tried, and failed initialy to see what was in it. I thought my phone had been hacked. I then did a quick search and discovered it was a feature and that by looking in Settings | Apps, and looking at all the apps, that I could determine which - if any - apps were included in this group (There were none).
I can understand why Apple might have been asked to put in such a feature: many people would want this feature: especially families who must share a single device for all of their computing and communication needs. Even at tje basic level, these devices aren’t cheap, but they open up worlds and access to services many of us here might take for granted. Far from hiding unseemly or even nefarious content and applications, the ability to keep some users of the phone from, e.g., making unapproved purchases on Amazon or getting into other such apps to make purchases or change account settings for any number of things, certainly would appeal to many. Others have mentioned other situations where this could apply, as well as unintended consequences of such a hidden set of apps or data.
What would really meet the many needs of the users would be to make iOS a true multiuser platform from the end users’ perspective. Parents, could create a “sub-login” for their individual family members. In each account, they could specify what could be seen and used on their own screen. In this example, the kids would have their own face-id for login, and they would see the few apps that the main user wanted them to see. The Parental control scenario…
I would opt for an enable/disable setting in Settings, with Disabled being the default. However, this whole concept is not an easy one to implement, and it is full of problems and unintended consequences of it’s own. I imagine Apple chose the current feature implementation as the lesser of several evils, though I have no direct knowledge of their processes.
I encourage you all to keep thinking about this. I would rather have the ability to disable this feature as I don’t necessarily have need of it. Thank you for your patience and attention!