Unless my understanding of how IPv6 is flawed, I don’t think your assertion is true in practice. One of the big benefits to IPv6 is that addresses are plentiful and fairly disposable. Getting a /48 block and configuring a router to assign from the block is pretty straightforward.

I’m aka unsure if IPv4 really gets you the privacy advantages you think it does. Your IP address is a data point, but the contents of your TCP/HTTP traffic, your browser JS runtime, and your ISP are typically the more reliable ways to identify you individually.