Why was my apps removed??? Without being advised

Apple can remotely disable apps on your device, but they will only do so if an item from the App Store has been found and proven to be malicious. In short, it rarely happens. I Am Rich is one such app this happened to.

Otherwise, a vendor can remove their app from the App Store at any time. You'll still have it on your device, but you won't be able to download it again if you've deleted it. I've had that happen to a few apps over the years. Both paid and free.

There have always been free and paid apps.

A free app that is downloaded to a device cannot be removed from the device unilaterally by Apple.

Any apps that have been deleted from a device and be freely redownloaded to it form your purchase history, even free ones.

What ever happened to your App, Apple has nothing to do with it.

Maybe you unintentionally hid it? Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support "If you turn off an app or feature, the app or feature won't be deleted, it's just temporarily hidden from your Home Screen."

See if it is in your App Library -->

Organize the Home Screen and App Library on your iPhone [iOS14] - Organize the Home Screen and App Library on your iPhone - Apple Support

"Search for it ( Use Search on your iPhone, iPad, or iPod touch - Apple Support ). Swipe down from the middle of any home screen and type the name of the app into the search field at the top of the screen. If it is in a folder, it will show the folder on the right of the app name after you tap on the app when it appears in the search."

"Reset the Home screen layout which will return the [app] to the home screen as long as it isn’t restricted. When you do this, it returns the home screen to out of the box condition and it will destroy any folders you had on the home screen. Settings > General > Reset > Reset Home screen layout."