Safari

The Safari app is not one of the apps that can be deleted but it can be removed from the home screen. Go to the App Library (swipe left past your last home screen). From there you can touch and hold an app and add it to the home screen.

Also note the Search window at the top of the App Library.

Another reason for it not being visible is due to a restriction. Go to Settings and tap Screen Time, tap Content & Privacy Restrictions, tap Allowed Apps. Also see the following Apple Support article for more information: Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support

How to use the App Library:

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

An easy test to see if Safari is still installed is to find an internet link in an old email or text message and tap it. If it opens, Safari is still installed.