Just time and the inevitable squeeze of censorship on all other communications.

It's completely impossible now for governments to avoid taking full control of social media (leaving aside the possibility if trump gets in).  They are too committed and it makes too much sense for them.  

When that happens nostr will be the only option for free information, just as bitcoin will be the only option for free economic exchange.  I expect we'll see some major figure realise this and release content on nostr that cannot be shared any other way.  Then they'll try to shut it down and when they fail it'll be all over.