Yes we see "captive" retirees in Mexico. They move here because they can live on SS along with some other meager sources. They sell their home and buy one here for half price.
It is a nice safety net but, when it is mandatory, it feels like prison.
Agree with your assessment.
Back in 2007, I planed to RE in Vietnam in a few years (2009 or 2010), but held back the plan for various reasons. I am glad that I did that, otherwise, I would be stuck over there. I retired last June, and can stay in the US or Vietnam or anywhere for that matter. Just love the options.