Graphite is not exactly a high tech material. Maybe you're thinking of graphene? The process they use to create the small holes is also very cheap.

Graphite is high tech if you are living in a place where there is no mains electricity. And if you had mains electricity you would be able to use a simple electric still. So I'm still not convinced that this is actually useful in the real world.

There are plenty of places in Africa (and no doubt Asia too) with shops selling factory-made goods, but no electricity.

Graphite is more portable than mains access.