Hidden Apps are showing in App Store.
Apple has been revealed the hidden App feature since iOS18. However hidden apps are still visible in App Store, then what’s the meaning of hiding the App.
iPhone 13, iOS 18
Hiding an app only hides it on your device screen and can be unhidden if someone has access to your device with a Passcode. It is still visible in the App Store, Screen Time and in the Battery Usage setting.
Lock or hide an app on iPhone - Apple Support
It is actually just the same as Locking the app, but also removes it from your screen. This prevents a person from running it without knowing the passcode to unhide it. A locked or hidden app can't be downloaded from the App Store and launched to reveal any of your data associated with the app.