You're right, my 100B per square millimeter undershot by six orders of magnitude.

I woulda thought 18 quintillion would've been enough addresses for the next century or two but good thing we locked in all this extra data we throw away with a '::'.

I'm sure it was all well considered by intelligent people, but it was still a dumb decision.

What problem does 128 bits cause? Just that you don't like :: for a run of 0s? Do you need to care about ipv6 addresses in your work? Because I can tell you that when I'm trying to design simple, efficient routing and firewall rules (with e.g. 100s of thousands of endpoints across different datacenters on different continents), it's really nice to be able to subnet things the way I'd like instead of the way I must to squeeze things into the space I have, and not have to worry about backing myself into a corner later because I gave the wrong number of bits to various dimensions. And worst case, if you somehow got it wrong, just give yourself an entire /64 or more to try again, with it being compatible with what you did (no need to do a phased migration that requires reclamation as you go along).

Like I only tangentially interact with this stuff, but I can't imagine how a network operator wouldn't prefer we live in an all ipv6 world.

Don't forget you want extra bits for hierarchical routing. Companies like Amazon and cloudflare have many separate address blocks instead of one big one because that's what was available, but it means every router in the internet has to remember all their blocks instead of just one.