So, IPv6 is designed to embed IPv4, standards are witten, all software manufacturers start implementing IPv6 that includes v4 (i.e. understands 16 byte addresses as well), but network equipment manufacturers (according to you) do not implement this at all because they cannot redesign their ASICs to do that in almost 10 years. And on top of that, ISPs do not buy a single new router in that time.
Ten years ago all Cisco routers were routinely accessed via telnet. These days folks mostly use ssh. Things change when the right signals are given.
IPv6 transition is being handled rougly like the 2000 bug. At the last minute people are scrambling to cobble together workarounds. At least old programmers had a good excuse - space was at a premium.