[reincarnate0x14]

It was fixing (or trying to) issues with the v4 spec that were now very apparent.

For example, ipv4 technically has a link-local address space but barely anything will use it and even less will successfully. Many other 80/90s protocols did much better at that (IPX being an example) as well as having distributed name and service locators and such.

IPv6 local networks of IoT devices or whatever can pretty much automagically start communicating with zero configuration to anything else locally. No DHCP or whatever required.

The world didn't stand still between v4 and v6, it'd be weird if the protocol did.