It's usually unlabeled buttons, unlabelled icons, divs that change color on click instead of actual honest to god native HTML checkboxes, inaccessible drag-and-

It's usually unlabeled buttons, unlabelled icons, divs that change color on click instead of actual honest to god native HTML checkboxes, inaccessible drag-and-drop, no heading structure which makes navigation harder, weird date pickers that screen readers cannot handle and so on.