Never.

> The [ipv6] address space therefore has 2^128 = 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses

https://en.wikipedia.org/wiki/IPv6

If for some crazy reason you wanted to give each byte of memory and storage in a supercomputer its own IPv6 address, you'd be able to scale up to 300 septillion (301,936,594,947,653,725,323,264) nodes, each with 1 terabyte of RAM and 1 petabyte of storage, before IPv6 ran out of individual addresses.

That's not even counting the 65535 ports you could then use.

It’s not about how many devices you have. It’s about how many ports you have listening on each device and how frequently they hop addresses.

Globally yes. Each network has far fewer.