Once upon a time, luggage handlers dealt with fewer flights and less stress and took more care with passenger luggage. Unlucky for us, the times have changed, and a dented or broken suitcase can often be par for the course when traveling internationally. Placing a 'Fragile' label on a suitcase in the past may have made a difference, but we hear that baggage handlers today pay zero attention to special labels on suitcases.
Instead of relying on a label, our pro tip would be to ensure that any breakables inside checked baggage are well cushioned in bubble wrap and padded all around by clothes. Have we learned nothing?!