I think about this frequently. IMO, geographic sparsity is the biggest difference. Every malcontent on the planet just can't reach my door, and the physical reality of movement through space means they can't reach my door, AND every other door on the planet, in the same way they can reach every IP, or practically every IP.

There's probably a field of study with vocabulary and accompanying proofs of significant rigor that prove or disprove this. Maybe they'll stop by our little subthread and clear it up.