Today Example Co can go to the courts and say "we own the name 'example', so we should have example.com". This works in many countries today. (Or they can offer current owner a sum of money).
With GNS they would have to lobby all sorts of GNS providers. That's a worse situation.
Similarly "buying the domain" simply means having this party yield the registration at the domain registrar to you.
Anyway, both also works in GNS. My example addresses the case where the legal claim is not possible and the other party uncooperative while "consensus" is that it is a squatter with no claim. (Or, by extension, a censorious circumstance, think TPB)