I agree with this but I would say the prefix is the only thing you should focus on.
It's important that ISPs don't regularly rotate your PD and it's part of the rfc recommendations that they don't. And the remainder of the prefix is your vlan space that is as important for VLAN routing as always.
It's honestly super simple to set up. Outside of your ISP config it's almost all autoconfig. 100% of the complication (at least for me) comes from knowing ipv4 first for 20 years and then trying to incorrectly map those concepts to V6.
As soon as I "let go" it was fine.
There's not a huge net benefit you're right. I mostly wanted to learn and I hope to be at the front edge of disabling ipv4 in the near distant future.