Only the visible homeless problem. There are plenty of homeless you don’t notice because they aren’t raving like a lunatic without a shirt on. We have two separate problems, but they are sadly often conflated.
"Definitely the result"? I think you might be confusing correlation with causation.
That really isn’t true either. Homelessness doesn’t cause drug abuse, there is plenty of drug abuse among the housed, it isn’t weird that some of them eventually lose their support network. There are definitely economic homeless in Seattle, they just aren’t as visible as the fent addicts.
> Homelessness doesn’t cause drug abuse,
Being homeless sucks. There's a number of reinforcing conditions that convert non-users into users.