Earlier quoted context omitted.
DEI in practice is illegal (we don't get to make decisions based on race, or other protected categories of a person's identity). I get trained on this once a year at work. What we do instead is improve the probability that underrepresented people can enter the hiring pipeline, e.g., by investing in schools.
Sorry, what's the difference between the former and the latter? My whole understanding of DEI is perfectly described by the thing you said is illegal. Otherwise, you did not describe what "DEI" is, so I hope you can understand my confusion.
All of the relevant laws specify that (1) you are not allowed to treat anybody differently based on their race, and (2) if your outcome numbers don't match what the government wants to see, there will be hell to pay.
Only (2) can be directly measured, so that is the part of the law that's enforced. People report that they treat all races equally for the same reason that Soviet agriculture officials reported that the grain harvest was better than expected.
† It's not clear to me why a rebranding was felt to be necessary. "Affirmative action" was popular; a lot of the loss in status of this type of initiative seems to be fairly directly related to the fact that, once the name was changed, people could reevaluate the concept without being confused by the preexisting knowledge that they approved of it.