I'm a first generation college grad (both undergrad and grad school) raised by blue collar peeps (sort of - it's complicated). In professional environments, talking about your life or the impacts of poverty will get you pushed out. You're not a 'culture fit', you make people uncomfortable, the upper-middle class/PMC assume that if you have poverty problems you can't work as well, etc.
It is 100% passing. I'm very good at it, because my mother was a defector from that life and passed on the social mores for us to use, but I hate it, and the energy it takes up is immense. I didn't even realize until I worked in my first 'non-professional' job in retail. I don't have to hide everything about my life and childhood, I don't have to watch my language so I don't give away I grew up poorish, etc.
And I have it very, very good in my groups. (Poor-raised + disabled).
Regardless of that there are benefits to be had here. Very few products (especially tech products) are targeted exclusively towards people from wealthy backgrounds.
Cori Bush was once homeless. I guarantee she will work harder for people in need than Nancy Pelosi ever will.