This is it. So many retirees are too poor to live in Western countries, let alone live well. They have a small pension (if that), some old age benefits, maybe some paper wealth in real estate that they can't access because the cheap cost of shelter from that real estate is critical to making ends meet. If they get divorced, then they probably need to sell the house, so no more cheap shelter.
Moving somewhere cheap is their only option to have a dignified retirement. Of course, that probably is just delaying the inevitable since older age comes with all sorts of health issues and at some point they will probably need health and elder care they can't afford in their home country.
I heard cigarette taxes are the preferred form of sin tax because typically smokers pay more in taxes than they use in healthcare etc on the way out. Nicotine addicts die fast and are tax efficient, unlike alcohol or gambling addicts.
Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn.