I think you might be underestimating uptake. Google suggests upwards of 50% usage. Also I’m fairly certain that a lot of residential infrastructure has been slowly moving to IPv6 in Australia at least. Not an overnight process, but it’s happening. Over here we have a lot of newer mobile plans offering IPv6 as well.

I think a big holdback is that a lot of larger corporations will still use IPv4/NAT setups at the top level, even if all of the hardware in the network supports it. “If it’s not broke don’t fix it.” The result is huge amounts of daily traffic coming from these institutions being IPv4 by default, with all devices in WiFi, etc, being lumped into the same group.