[zAy0LfpBZLC8mAC]

The benefit of not having addresses collide. I mean, that's the whole point of assigning globally unique addresses?

When you connect some previously unconnected networks (a merger, or simply access for some sort of cooperation, or for maintenance access, or whatever), it's a nightmare with RFC1918 when address ranges overlap, which they invariably do. If you use globally unique addresses, you can be sure that there will be no problem.

When you debug something, you don't have to figure out what maps to what where in the network. When two machines talk to each other, the packets are labeled with the IP addresses of those two machines and the ports they are using, no matter where in the network you investigate. No matter who writes a log file about some operation happening in the network, all of those log entries are labeled with the same, uniquely identifying addresses.

And on the other side, there is still exactly zero benefit to using ambiguous adresses.