I will fully and honestly admit I don't understand much about IPv6 - however, I have a question - why didn't they just add 8-32 bits to IPv4 and call it a day?

Legacy IPv4 would be trivial to support via NAT, and we wouldn't have to deal with address shortages either globally or locally. I'm sure every sysadmin/cloud person dealt with having to arrange subnets by hand, or the fallout when you just ran out of addresses and had to tear down multiple layers of routing just to make more address space.

Computers default to 64 bit integers, I don't see why this couldn't be done on the network.