Minecraft: construction block?

I play on iPad (IOS) Minecraft PE, my question is why you can get a construction block via Command, because this block in the PE version actually does not do any good, so why is it even available in the version?

From version 1.13 the construction blocks work. But you have to activate in the settings of your world but the "Experimental Gameplay". Tutorials to use these can be found quickly on the Internet.

Thanks