Rather than solving the problem the pragmatically (and in a backwards compatible way), we're pushing a reinvention of the wheel (protocol).
IPv4 certainly has problems but I think they were solvable without bisecting the internet.
If you look at the TCP packet, bits 16-31 are constant for all HTTP traffic. Because they are a fixed value, they're wasted (non-unique). With the current system, we can only have 2,147,483,647 web servers.
Using SRV records, these bits become distinguishable, giving us 281,474,976,710,656 possible addresses for web servers.
[Yes this is an oversimplification for the pedantic]
On the downside you won't be able to easily tell if two services run on a same machine or not. SSH and HTTP endpoints would be related only through DNS.
I think doing it in compatible way that doesn't require replacing routers would require NATs on both sides, and client that looks up PTR records before connecting.
The network space is huge, but segmented. At each branch of the network, you reduce your addressable space significantly.
When you think of the future, and huge interconnected small devices, I don’t think 128 bits are going to seem excessive.
Remember, when they came up with 32bits for IPv4, they were not planning for a computer (or multiple!) in your pocket that was going to be network routable.
One can see from IEN28 in 1978 that early forms of 32-bit addressing, at the time comprising 1 octet network, 1 octet IMP, and 2 octets host, weren't even planned as extending beyond ARPANET.
I think the main idea is that you want to have plenty of space both for growing horizontally and vertically, at least enough to where you can't even imagine exhausting it in either direction. Giving massive private and public address space without need for NATs effectively provides this.
Also, hey, who knows. There isn't enough raw materials on Earth, perhaps, but maybe there are enough raw materials in the universe. Who knows for sure if the Internet always be confined to just Earth.
To simplify routing, only a small fraction of the address space will be used.
At least that's how I understand it. Think of it like this - GPS coordinates are longer than post codes and less efficient for storing the location of people. But as a bonus finding someone's location using coordinates doesn't require a huge database of post codes.
Similarly, coordinates have a huge address space - every location on the planet, but we don't expect people to actually live at every location - in the ocean etc.
Assuming you're responding to this? That statement is unwieldy but clear (would have preferred there aren't even enough IP addrs to uniquely identify every currently living person or some such).
In practice there'd be some introductory issues in deviating from the well-known ports involving gateway traversal (particularly corporate firewalls), but we've cleared such hurdles before.