but is there any actual way that actually passing this rubbish on actually does any good to anyone?
No. If you truly want to do good, volunteer for a charity and share the event information with your friends. Forwarding spam is forwarding garbage. A bit worse as it leaves a bad taste in the mouths of many recipients.
If I receive a joke or something that at the end says to forward to a bunch of people, I tend to remove the forwarding blurb before sharing it... I'm that opposed to the forwarding of spam.