Instead of the numbers you type in the hostname of a device. IPv6 encourages to improve on the current lackluster DNS solutions some routers have.
Three trouble begins at internet scale where mDNS just does not work due to collisions. And ISPs do not want to give you free domain names and especially free dynamic subdomain delegation.
>And ISPs do not want to give you free domain names and especially free dynamic subdomain delegation.
Probably not but for internal resolution a .local or similar TLD is sufficient.
"Server IP address could not be found."
5 minutes later...
"Now could you please tell me the IPs of all connected devices?"
Customer hangs up and cancels his subscription.
So, with that in mind, what would be the major drawbacks to IPv6 address shorteners? You'll always have a certain class of issues such as transcription errors, of course.