I wouldn't worry too much. "free" social media is the cornerstone of surveillance capitalism. They will try to ignore it, even suppress discussion of it (like Twitter did), and then before you know it, DAU growth of Nostr will outpace all other social networks and the network effect will do the rest. Most of the incumbents are tapped out for new userbase. They simply don't have any further growth potential.

And they already have all the rails and pathways for their favourites to get closer to the fiat spigot. It just isn't a profit opportunity for them, and even if they try it's gonna be johnny come lately.