You have to take extra steps to ensure that the benefits of NAT aren’t lost when you switch to ipv6. Everyone knowing exactly which device you’re using because a single ipv6 IP per-device is the default.
Ipv6 is nice, but also you need to know what you’re doing to get all the benefits without any of the downsides.
Not access, knowledge. Giving a specifically unique device identifier every time you visit a page is different from the website guessing if you visited recently based on your screen size and cookies.
You have to set up ipv6 to change regularly to avoid that.