FWIW, you aren't (arguing a tangential point to me): I didn't say "one of Facebook's servers goes down", I said "Facebook goes down". Companies go out of business or simply get tired of operating product lines constantly. I can sort of appreciate the idea "well maybe by goes down I just meant temporarily", but then I think one needs apply that to the entire sentence: if it goes down permanently, the accounts are no longer usable permanently (aka, "destroyed"); and, if it goes down temporarily, the accounts and data are no longer usable temporarily.
I don’t think I am; all these fall under GP’s first sentence; I took “goes down” in the next sentence as one example, WLOG.
> Are crypto maximalists arguing that social networks are only about the database itself and access to it?
I can’t speak for crypto maximalists (I’m probably as skeptical of this stuff as you are), but I think the best argument is that the existence of a viable off-ramp forces the centralized player to be a good actor. Similar to how many open source projects are very centralized, but the possibility of a fork (like mariadb) is enough of an incentive that it’s rare for a project to screw up so badly that a fork can gain steam.