Mostly because all of that is a highly-confusing tangle. Food stamps are hilariously limited in most states, same with Medicaid. Section 8/HUD will almost always make sure you wind up living in the most run-down tenement your town has, run by the shittiest landlord, who will almost always be looking for a reason to evict you - and that even assumes you don’t have to wait literal years. The current wait time for Section 8 housing in my city is something like a year and a half.