I don't want to make too many assumptions here because it's a bit of a minefield, but... perhaps there's an entirely selfish and rational explanation for DEI hiring programs in a tight labor market? If you feel like you've hired all of the labor you can at a given market price (e.g., you're cheap and don't want to pay people more) it might make sense to try and reach out to parts of the labor force that you feel have been underutilized (or historically underrepresented, but we're looking at this from the perspective of a ruthless business), and DEI programs could be a way of achieving this.
I don't think that's an entirely accurate narrative, but I do think it's probably at least part of this (e.g., that all of the best white people were already hired, while many POC people of equal caliber were not or not making as much). The job market was soaring in 2021 and looking for ways to hire new people without having to pay them more would likely be highly attractive. Now that the job market is not so competitive, there's not as much need to do so if you're just trying to find workers.
