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