>DEI initiatives are inherently sexist and racist and to date I have seen zero solid scientific evidence proving that diversity is a strategic advantage

I can't speak for the broader, more recent term of DEI, therefore I am not speaking to how diversity is achieved.

However, I can speak to diversity being a huge win. I've seen features go through the lifecycle process that if there weren't other perspectives in the room (namely, people of color, non male genders and folks with disabilities), we would have ended up releasing things that would have either not been good for our entire addressable market, or accidentally offensive.

Saved us embarrassment more than once. Having a pool of people from different backgrounds, ability, ethnicity and genders can be real value add, in above their competency as engineers (of which, they most certainly were some of the best I ever worked with in many cases)