What are the practical consumer-level implications of this? My understanding is that every internet-enabled device needs a unique IP address. If there are no more unique addresses, can no more devices connect to the internet in this region?
One cable company used to do it in Brazil back in the 2000's
This is where many people can share one IP. But NAT has problems - you can make connections, but you can't accept connections from elsewhere. And it sometimes breaks particular applications.
The only real solution is widespread IPv6 adoption, which seems depressingly unlikely right now.
Slow maybe, but unlikely? No, not really. IPv6 internet has grown fairly steadily (and afaik at a growing pace) since its inception and I don't see any reason why that trend would slow down or stop. There hasn't been any real opposition or alternatives for IPv6, mostly just indifference and ignorance. More and more new gear supporting IPv6 natively out of the box is being deployed on the field, reasons for not enabling it are dwindling. XP just got deprecated, most end-user stuff probably already supports IPv6. Old network engineers retire someday, and new generation is well aware of the issue at hand.