The world is already managing with 32 bits of addresses plus NAT, and NAT most likely gives you less than 256 concurrent users per address. But sure, if some cheap ISP only owns a few /32s and needs to use more octets, let them do that, doesn't mean my 4-octet address needs to be super long too.

You're kinda forced to use 128 bits in v6 if you're an end user, cause that's the lowest common denominator. SLAAC is default, DHCP6 is widely unsupported. Most ISPs also only give out a /64 per spec minimum.