Add cq:noDecoration property to component node with value "true" in whichever non-editable component where you don't require component wrapper div to get generated with class name(for ex: the div generated with class name 'customDropdown' for that specific component in your example). by adding this property with value "true" will avoid generating wrapper element.
For editable component, ideally there should not be any UI issue because of this component wrapper div element. so, add css style changes accordingly if in case there is any UI issue.
The wrapper element should be added to all components that are editable, so that the page editor can initialize and update them properly.
For non-editable components, the wrapper element can be avoided if it serves no particular function, so that the resulting markup is not unnecessarily bloated.
<div class="customDropdown"> <!--this wrapper div element will not generated if cq:noDecoration = true property added to customDropdown component node