It's not left out. It's well studied. It's not the only factor, but one of the big ones. The problem is, median black net worth is one-tenth that of median white net-worth. Why is that? You can come up with a bunch of near and intermediate causes, but they will all mostly boil down to systemic racism both past and present.

More specifically, government housing is only available in dense urban environments. As is public transportation and services within walking distance. The black population is much less likely to have any generational wealth (like a home or even an old car passed down to them) obviously due to historic racism. Then pile on the fact that urban areas are more heavily policed and the fact that over-policing seriously hinders economic prosperity, then you have a textbook definition of a vicious cycle.