Homelessness expert here. This data set is garbage. HUD data only includes those in the federally mandated HMIS (Homeless Information Management System). This data excludes 1) people who don't access services; 2) people who access services from private, non-federally funded programs (like faith-based groups); and 3) typically undercounts those with SUD, mental-health issues, and especially people of color.

A recent BGC study estimates that, in Seattle, for example, HMIS data doesn't include up to 40% of people in encampments.

Garbage In -> Garbage Out. Pretty sweet effort, though. Wish the feds were smart like this.