> Fast forward a couple of decades and everyone needs 10 IPs each. You have your phone, your laptop, your work computer, your TV, your door lock, your door bell camera, your thermostat, etc.
Your phone perhaps, but the rest of these devices never need a public IP address.
We should abandon the very idea of "public" and "private" addresses. An IP address is just an IP address, a globally-unique number that identifies a networked device. If you want a device to be inaccessible by other devices, throw in a firewall. NAT is just a firewall with packet-modifying capabilities anyways.
Your phone never needs (nor gets) a public IP either.
Pretty much every cell network gives the phone an IP on the subnet, and then uses NAT, or CG-NAT[1] to share the same public IPs for multiple mobile devices.
Your phone perhaps, but the rest of these devices never need a public IP address.