Why it matters.
A white region may hide texture that later editing cannot recover.
A closer look.
Histograms and highlight warnings help identify bright regions at risk. Reducing exposure can preserve more highlight separation, while making the rest of the image darker.
Picture this
Check a sunlit white shirt, then reduce exposure slightly and compare whether its folds remain visible.
Keep in mind.
A bright light source may reasonably clip. Judge the important subject detail rather than treating every warning as a fault.