Now currently I'm not in the workforce, but in the past from my work experience, apprenticeship and temp roles, I've always seen ipv4 and not ipv6!
Hell, my ISP seems to exclusively use ipv4 (unless behind nats they're using ipv6)
Do you think a lot of people stick with the earlier iteration because they have been so familiar with it for a long time?
When you look at a ipv6, it looks menacing with a long string of letters and numbers compared to the more simpler often.
I am aware the IP bucket has gone dry and they gotta bring in a new IP cow with a even bigger bucket, but what do you think? Do you yourself or your firm use ipv4 or 6?
When I was first looking into IPv6, people were talking about how you can self-assign an address by simply wrapping an IPv6 address around your MAC address. But that practice seems to have fallen out of favour, and I'm guessing the reason is, as you say, the whole privacy thing? There's a lot of pushback these days against any tech that makes it easier to fingerprint your connection.
That was so insane - "we need a unique number, let's just use the MAC" - it was like people didn't even think through any of the implications when making ipv6 address schemes.
Similar with the address proposals that ignored the need to minimise the size of core internet routing tables.
IPv6 has privacy addresses, though. Stuff on my network generates a new random address every day and uses that address for outgoing connections, so you can't really track individual devices inside my network.
You can just look at what addresses from that range have left the network in any given 24 hour window.
If AAAA is constantly reaching our to aussie.zone one day, and the next day AAAB is reaching out to that address you can pretty easily connect the dots.