Here's the thing: cities don't provide social services in order to attract the homeless from surrounding areas. That would be nuts. Who wants to be a homeless magnet? Cities provide services for the homeless because they already have a critical mass of "homegrown" homelessness. This may attract some from surrounding areas, but the critical mass would exist regardless, due to economic conditions in the cities.
Both Canada and the USA have freedom of movement without a residency system. It doesn’t matter what social services the city provides, the cities can’t discriminate who they provide services to based on residency.
None of this is new. The trope of a hobo jumping a train to San Francisco is as old as movies are. Seattle has always been a destination for those without means looking to survive. The original skid row was in Vancouver, Seattle, Portland, or Spokane depending on who you ask, and that goes back to the late 19th century.
Seattle does not want to be a homeless magnet, but it always has been, and the city is too progressive to cut off its generous social services, and can’t discriminate with them, and they can’t do anything about the weather anyways, so what the heck else can they do?
It has a lot to do with economic conditions: a well funded city (comparatively), plenty of things to steal, and a reluctant acceptance of property crime are all important in making freattle a destination, the same with the other west coast American and Canadian cities.
