No one is discriminating for the sake of diversity.
Companies that lack diversity, however, are failing themselves.
https://observer.com/2017/01/diversity-workplace-economic-returns-hiring/
Edited to add
Since you apparently have a problem with the McKinsey study you might like to take a look at some others.
https://www.weforum.org/agenda/2019/04/business-case-for-diversity-in-the-workplace/