> Remembering and communicating mildly complex byte sequences should be an issue which is solved already.

It is solved already, it's called DNS.

...except when DNS doesn't work.

IPv4 addresses are not any more difficult to remember than phone numbers, but the same can't be said of IPv6.

I agree, lets limit the total number of internet devices to 4 billion just in case we need to memorize one of the addresses.

The other 4 billion people on the planet don't really need internet connections do they?

The counter-proposal to IPv6's 128-bits was 64-bits. This is 16 quintillion devices, which seems fine.

Doubling the address space is a good strategy when you need more. Quadrupling it is over-engineering.

The extra space means you never have to calculate subnet sizes and you can let devices handle their own IPs. I think that's a pretty good tradeoff.

64 bits are already a pain in the ass to remember, and if you have specific memorization needs you can use small static IPs so that even with 128 bits available you only use about 64 of them.

What's the benefit to 64 bits? They're still hard to memorize and they're still not going to be backwards compatible.

It's a good strategy if deploying a bigger address space is easy and cheap. When it's incredibly difficult and time consuming, you should pause and consider a bit more carefully.

New L3 protocols on the Internet are firmly on the "incredibly difficult and time consuming" side.

Diceware is way easier to share over the phone than any IPv6 address (except for the few vanity ones like Google's 2001:4860:4860::8888 — then it's only slightly easier).

https://www.eff.org/dice