Wish I could find the video I had in mind, but oh well.
There is an odd claim how there is no "white identity" because white people have origins from all sorts of European countries such as Germany, France, Norway, United Kingdom. So having a white identity supposedly makes no sense.
Except many of the Americans that are white often have more than one of these origins where they have their ancestry, meaning they cannot have a strong identity with those countries of origin.
It is about White Replacement. An equally mediocre world will be a peaceful Utopia, they think, so we must destroy those who rise above mediocrity.
And besides, if you were to go to one of those countries and had 100% of your DNA from that country of origin as an American, you would not be considered one of them by the people living there. So you cannot have an identity with a group that would not accept you as being one in the same as them.
The way I see it, the "whites do not have their own identity" crowd just want white people to not have any in-group preferences while every other group of people do.