My guess is mostly mobile traffic?

I run a personal tech website containing OSS projects, and have been supporting v6 for more than a decade. Currently seeing few hundred unique visitors per day.

IPv6 has been steady at ~15% of all inbound requests for the past 5 years, with zero signs of increase.

Both my own fixed adsl service and a different mobile carrier do not offer v6, so I have to jump through hoops to verify my server setup.