Space in interfaces is limited, especially in complex applications.
Fortunately, the size of interaction elements began to grow as soon as we started to interact with our fingers on touchscreens. To make elements reachable we need to make elements bigger.
This doesn't mean that the element itself (like an icon) does have to be bigger. We can also add some space around the element that reacts on user input.
Take this action
Make the interaction area of elements as big as possible.
Human Interface Guidelines (from Apple) recommend a touch target of 44 x 44 reference pixels and
Material Design (from Google) even 48 x 48 reference pixels*.
* What is a reference pixel? With reference pixels we define sizes in designs. They are rendered differently on different devices – depending on the pixel ratio. Example: 1 reference pixel will be rendered with 3 hardware pixels on an iPhone 12, but with only 2 pixels on an iPhone 8.