If, suddenly, one billion people couldn't use Facebook anymore, then it would be because of a literal apocalypse. Facebook can't just disappear overnight.
You lack imagination, if the great firewall of China decides to block Facebook, poof, one billion less users. Overnight.
That is, if it's not already blocking it, probably is, thinking about it...
Also, Bitcoin is different in that, while Facebook severs can be shut down tomorrow (but highly unlikely), it's literally impossible to just shut down Bitcoin servers without bringing down the whole Internet in the process.
I argue that allowing the block size to grow is equivalent to making Bitcoin as vulnerable as Facebook currently is. In other words, centralized enough that it becomes vulnerable.
You first. If it's not trustless yet, it's not ready.
See you added the 'trustless' bit later on. I happen to disagree.
Anyway, it is my considered opinion that voting pools are pretty useless, because they constrain the OT servers in such a way that they have to be strictly iso-functional to all other OT servers participating in the same voting pools in order for the voting pools concept to work.