Alright, let me start by restating that I acknowledge socioeconomic reasons why the US may want to do this and that I'm not American and don't feel about this strongly. Others have provided more detailed examples in this thread and I assume those make some sense. I wouldn't know.
Now, that being said, either you're underestimating my awareness of public affairs enough that you've reduced this response to absurdity or your view of the whole process is kind of skewed. You absolutely have tools to know how big a socioeconomic group is without needing strict categorization or census data. And I'm going to go ahead and assume the US doesn't budget public aid based on handing out money to people based on race. That sounds more like a far right fever dream of how that works.