So, comments seem to agree that IP6 has far more addresses than anyone could ever need - so many in fact that every single networkable device I own could have one that was unique on the planet. And of course utterly impossible for me to remember.
As a non network person, neither of those looks like a good thing to me. ..
My ADSL router is 192.168.1.1, and also, very usefully when logged in at there place, so is everyone else's making logging into the thing to set up the firewall something that we have a sporting chance of managing.
Rather like knowing the toilet is upstairs over the kitchen in all the houses built in a given style it saves you having to ask, althhough in most houses the home owner knows where the loo is. they probably do not know the address of their own router
Each house has half a dozen items and they will be 192.168.1. something, and that one 3 digit no can be written on it in crayon if we need to know it for static routing.
as someone who does embedded programming where every byte of RAM counts, to waste two lots of 128 bits in every packet on source and destination seems a waste of RAM, clock cycles and microamps if the thing we want to talk to is on the same LAN anyway.
I suspect that the folk who want IP6 actually want to do things that are more complex, but they are such a small fraction of the total of computer users, that they are outweighed by the rest of us where routing for the backbone and the shortage of non-local addresses is of no interest - so long as the DNS works...
Would a simpler IP5 have caught on? Perhaps IP6 is it a bit like plan 9 one step beyond what is usually needed.
Mike