In 1916, during the First World War, the Germans dropped the idea of using the pickelhaube because it wasn't practical in the trenches. I read the wiki, but I am left with one question:
It remained in service for more than 70 years, it doesn't seem to be practical at all and its additional combat value looks negligible. Did it have any real practical use?
[Source: Dr Max Litthauer’s pickelhaube (spiked helmet) with camouflage covering, 1914–1918. Donated by Bart Ullstein © Jewish Museum Berlin]