You currently have an address hierarchy like <AS Number>:<Network Allocation>:<Subnet>:<Host>. That hierarchy is conveniently conveyed in a single 128 bit number. With an alphanumeric address, 128 bits of ASCII would get you `company:office:l` and your net/subnet/host would require more CPU horsepower to compute.
The ascii is for presenting to the user not for hardware processing. It is not a wire format. Onlh when logging or parsing a config (human interfacing) is an ascii conversion required and a modern protocol that wants adoption should prioritize human friendliess at the human interface of the protocol.
Right now the hex lets you mental model the wire bytes nicely but it is unpleasant to use. V4 used decimal which is pleasant to use. UX trumps all.
You currently have an address hierarchy like <AS Number>:<Network Allocation>:<Subnet>:<Host>. That hierarchy is conveniently conveyed in a single 128 bit number. With an alphanumeric address, 128 bits of ASCII would get you `company:office:l` and your net/subnet/host would require more CPU horsepower to compute.