I have been thinking about this quite a bit, recently, as well and I do think the future does look like something you described. However, I do have doubts. Outside of being worried about the big brands removing your access to your hard earned reputations (which seems unlikely on a mass scale), what would be the other common uses cases for a crypto identity key? As we know, in order for a majority of people to adopt new technologies, there has to be a very compelling use case. I am not sure a consolidated identity key solves any real problem or rather it is just a cool tech thing that us hackers would like to see, kind of similar to the problem that bitcoin in general is having in achieving adoption.
I am curious if you guys have any really good thoughts on products that could implement a crypto identity key that solves a real life problem. Would love to discuss.