My point is that you don't own your handle. Therefore you aren't your handle.

Edit: to clarify: You aren't your handle, because it can be taken away from you, can be injected, blocked, overridden, etc.

My technical rambling then went on about how or when we can make this "handle" decentralized so it cannot be taken away from you. Hard. As proven in practice. Almost impossible.

My name is maintained by a government. It is a "handle" that could be taken away too, but is governed in lots of rules, systems and regulations. My face (an extension of my DNA, I guess) is decentralized and owned by me: its the only handle that afaik no one can take from me.

So in social interactions, you're right: reputation, bound to "me", my face, my DNA is all that matters. But online we don't have this. The closest we can probably get is "my name", controlled by governments.