The point is that Germany saying "you can't contact someone by email unless they want you to" is practically unenforceable in the real world. So it's pointless.
It’s regularly enforced… are your local laws pointless because other countries aren’t concerned? Is free speech in the US pointless because North Korea or China doesn’t respect it?
It's hardly pointless since local companies are more likely to profit from spamming because there is an inherently wider range of things they could sell you - so even just getting rid of them helps.
But that also doesn't really matter to this discussion - the law existing provides evidence that not wanting to receive unsolicited corporate communication is not a fringe opinion.