How can I hide the App Library?
iOS does not offer a way to hide or remove the App Library, unfortunately.
How can I make it harder to access?
A great way to manage this is to add the Dumb Phone’s “Spacer” widget to adjacent Home Screen pages so the App Library isn’t a simple fidget swipe away.

Having the App Library at least 2 pages away from your main Home Screen page makes a big difference with managing fidget swiping after unlocking your phone.
You’ll now only see a blank page when swiping left. (on iOS 18 and earlier)

See the related article below for more details.