You might have seen various post on fetching dependent picklist values defined on fields in Lightning Web Component. Did you ever came across requirement to
REFRESH STANDARD COMPONENTS FROM LIGHTNING WEB COMPONENT
ADD QUICK ACTION IN HIGHLIGHT PANEL ON CASE OBJECT IN LIGHTNING EVEN IF FEED TRACKING IS ENABLED
RESET LIGHTNING INPUT FIELD ON BUTTON CLICK IN LIGHTNING WEB COMPONENT
A very common use-case in Lightning Web Component is iterating a list over an array in HTML file using for:each or iterator directive. Many times as a developer, we have to do something on the items based on user interaction. You would definitely require to get selected record id from custom iteration.