For those of us running networks, especially growing networks, uniquely numbering hosts is our goal and ipv6 fits that task.
For many networks, rfc1918 space is not sufficiently large to number end-points. Around the world, there are many networks that fit this.
For those same network, nat44 scale is also a painful and costly effort.
To that end, ipv6 / 464xlat provides the one-two punch of uniquely numbering nodes and by-passing NAT44 or NAT64 for the majority of traffic we see (google, fb, netflix ...)
Being able to offer a product that disallows access to ipv4 is a non-goal
So far, i just talked about why eyeball networks deploy ipv6 — which is basic and sensible engineering and economics. A similar set of forces are at work on the content / cloud / iot side.
Masataka Ohta