Such cases are a very tiny minority of homeless people. The vast majority go unnoticed because they don't "look" homeless. 74% of homeless people aren't drug addicts. 43% of homeless people are employed. Most sleep temporarily at friends homes, or in their cars, or in shelters. Homeless youth especially tend to blend in. Most people experiencing homelessness and housing insecurity do so because of economic reasons like high housing prices, poor employment opportunities, and low wages, often coupled with medical disability. The next leading cause is people escaping abuse. And homelessness is merely the most extreme case of housing insecurity, which affects around 12% of Americans.

The idea that we can't do anything for 4 people because 1 of them has a drug problems is absurd.