Tbf it's interesting data because if Detroit is selling 1 million in 2023 years after launch it gives us an idea of what some of the other "old" PS4 games would be doing per year
Likely more id assume.
Here the trend of Detroit sales updates previously:
9,000,000 21st Dec 2023
8,000,000 18th Jan 2023
6,500,000 18th Mar 2022
6,000,000 21st Jul 2021
5,000,000 03rd Mar 2021