π€"Unions are better than DEI!" is a very confused statement. Because unions and DEI address completely different problems.
One important thing that effective DEI does, is address anti-Black racism. It makes the workplace tolerable for your Black coworkers (if you have any).
Every public school teacher in the US is in a union. And yet, Black teachers and Black students experience massive amounts of racism from those teachers. Because unions aren't a magical answer for anti-Black racism.