Here is a step-by-step guide on how you can remove the suggested contacts list from the Share sheet on your iPhone.
Before proceeding further, make sure your iPhone is running the latest iOS version or the iOS 14 or later. This won’t work for iOS 13 or earlier versions.
Step 1: Open the Settings app on your iPhone.
Step 2: Now, tap on the “Siri & Search” option.
Step 3: In there, toggle off the switch for the “Suggestions when sharing” option.
Now, when you tap on the “Share” icon in any of the app on your iPhone, you will see all the available or applicable features, except for the suggested contacts list.