First introduced with the iPhone 6s and 6s Plus, 3D touch brought pressure sensitive functionality to Apple's screens. Every single iPhone since then (minus the iPhone XR and iPhone SE) has included the functionality but with iOS 13 Apple will likely pull the plug on the feature. The loss won't be that noticeable as Apple will simply transition to Haptic Touch gestures which were introduced on the iPhone XR and offer identical functionality without the need for a pressure-sensitive screen. Skimming through Apple's iOS 13 features preview, under the System Experience section we see...
Source: https://www.gsmarena.com/ios_13_cuts_out_3d_touch_in_favor_of_new_long_press_gestures-news-37428.php
