This is an interesting concept. The biggest disadvantage would be losing a digital archive every two years (or as necessary).

Its sister idea is holding on to phones for longer. The big drawback would be losing the phone, I think.

So does the person who finds the phone inherits the identity? Can we have influencers selling off their circles? When I get robbed is my mugger now friends with my grandma?

Isn't he already, right now?

Well, right now they would need to unlock it and I can sign out of the app somewhere else.

The phone would have the same physical security features. But 'signing out' would be more of an ostracism thing.

Ah, ok, so it's just a pain to get back into the social network. Isn't this just adding friction for friction's sake?

No, it's adding friction for honesty's sake. You don't have six thousand friends. You have five friends, tops, and like two hundred acquaintances tops[0].

There's nothing to "get back into"-- it was all just a lie to flatter you. The network effect stops working for you in the low three digits. You're just part of a people directory owned by some corporation.

0 - https://en.wikipedia.org/wiki/Dunbar%27s_number

For Facebook I keep my friends list light - less than 50 people, but there are people who I live a far ways away from - my parents for instance are 5 hours away. I don't want to have to drive to them just to prove they should be part of my social network.

I mean, if you want, you could choose to not use this nonexistent product. You don't have to hypothetically use it.

True, and I probably wouldn't. Just throwing out what I see is a potential issue.