I'm sure Apple, Ford and the US postal service are all using all 16 million addresses. The fact is that most intra-network traffic doesn't need an IPv4 address

I'm sure Apple, Ford and the US postal service are all using all 16 million addresses. The fact is that most intra-network traffic doesn't need an IPv4 address since it'll be NAT'd anyways. So even if Apple has 16 million IoT devices around campus, it doesn't actually need 16 million addresses. Fun fact, Stanford used to have an /8 but returned it since it wasn't using all it's addresses.