“more and more websites need to know something about who you are to work”
Ah, no. More and more websites WANT to know something about who you are, because your personal data is their money. The more you give them, the better.
You’re describing a single point of failure here, an excellent entry point for data collection, for profiling your behaviour, and to finally control your life. When someone restricts your access to this central login repository, then you’re out.
It’s the very same thing with the movement away from freely programmable production machines, to controlled consumer machines like smart phones, web pads and the like with the restricted app stores. The people are currently giving away the freedom they gained by the computer and internet revolution – and most of them seem to be happy in doing so.
Your dream WILL come true, because the consumer machines require such an infrastructure. But it will turn out to finally be a nightmare, I’m sure.