The reasoning in this case was that legislators had requested voter data by demographic, and later passed this law. It seems to me that they are making a correlation/causation link and I'm not seeing any evidence for that.
Why would they request a voter breakdown by race when the purpose of the law is to prevent voter fraud?
And it isn't about just photo ID's. They systematically inconvenienced people based on race, and the supreme court agreed. There is a clear causation. They closed voting places that were primarily used by black people. They changed voting hours to later in the day because black people tended to vote earlier. You seem to know a good deal about it, but the actual supreme court document seems to have escaped you.