> it is scarcity entailed by a (predominantly) private social arrangement where competing arrangements are permitted, but have thus far failed in the market
It's a network effect. The same reason it's easy to build a facebook clone yet nearly impossible to get it off the ground.
I don’t understand what taxing “network effects” has to do with Georgism though - Georgism argues land should be taxed specially because (1) there is fundamentally a finite quantity of it, (2) it is natural not human-made. Network effects don’t seem particularly similar on either front, and hence even if there is an argument for specially taxing them, that argument isn’t clearly Georgist - a Georgist could consistently reject it.
Closer to land are things like mining rights, water rights, fishing rights, pollution rights - taxing them is an obvious extension of the Georgist idea of land taxation, and it would be difficult for a consistent Georgist to oppose them, at least in principle
It's a network effect. The same reason it's easy to build a facebook clone yet nearly impossible to get it off the ground.