DEI programs are simultaneously for PR and morale. You don't want to be "that company that doesn't even have a DEI program". But also you don't want your employees being pissed off that you don't have a DEI program, because they could leave, or complain and decrease morale, which could become a PR nightmare.

But they can be more. Some companies I've worked for used their DEI programs to actively support local communities, organize volunteering efforts, collect donations. Even companies that HN might consider "Evil", I've seen have very strong and engaged DEI groups. It came down to two things: 1) they hired passionate people who took it upon themselves to organize internally and do more with the groups, and 2) they had leadership that (amazingly) gave the support needed for the group to make a positive impact.

But also, some companies I've worked for just had a 30 minute "movie lunch hour" and guest speaker and that was it. So it's obvious to me now when a DEI program is a PR dodge, and when it does real work.