Assuming no economic frictions whatsoever, which in reality is not the case, especially when it comes to someone moving their entire life away from their social network and their familiar surroundings.
My thesis is that economic frictions cause cases of homelessness that were theoretically avoidable. Their current social network isn't the only friction. Low IQ, mental health issues, no familiarity with COL or opportunities or people in other locations. These are other frictions. All the stuff that gets in the way of people making an optimal decision.