Apple may be backing away from 3D Touch somewhat—it isn’t available on the iPhone XR at all—but we’re still big fans of the options it offers. If you’re not, you can disable 3D Touch altogether.
3D Touch arrived with the iPhone 6s, allowing people to push more firmly on some elements of the iOS interface to carry out actions or reveal additional options. It offers a right-click of sorts, giving iOS some extra depth. It also adds complexity, though, and Apple has never been good at making the features 3D Touch enables discoverable. If you have an iPhone 6s or newer, excluding the aforementioned iPhone XR, it’s possible you have 3D Touch enabled and have never used it.