> Humans are the ones who have created such an overwhelming and toxic physical environment and disconnected social one

This argument isn't really theologically sound. If God exists, he's the one that created a biological system that allows for something as horrific as dementia. That literally has nothing to do with anything humans have done. It's pointless suffering.

> and to cause our contemporaries and descendants to suffer for our failures

Who's failures caused dementia? Certainly wasn't our ancestors fault.

Personally, I gain more comfort from the idea of an impartial universe, than a God who thinks this level of suffering is necessary.