I have a friend who did it for financial reasons to stretch her meager income/funds.
I've been following her on social media.
I'd summarize her last year or so there as filled with culture shock (in a negative way), frustration, homesickness for the states, and an overall sense of regret. What may have seemed like a fun and affordable adventure is now where she has serious buyers remorse.
I also knew a couple (friends of friends) who made a run at farming and living in Costa Rica. Small plantation, lots of fruit and bamboo plants, etc. AFAIK they did it about a decade but ended up throwing in the towel and coming back to the US. Not sure why, but I can make educated guesses.
For me, it would take a significant negative life change for me to pack up and leave the US and abandon my Constitutional Rights to live long-term elsewhere. I'd either have to be so rich it wouldn't matter, or so poor it wouldn't matter.
Visiting Mexico for a week is fun. But to move to Mexico to save a few bucks - not a chance. Being disarmed and having not Constitutional rights is among the top reasons; then there's the violent drug and gang crime, illnesses, lack of quality medical care, and laundry list of other reasons.
If you want to retire and stretch money, just move to rural or middle America. Houses and the prices of goods are sometimes 1/2 or 1/3rd of urban or more populated America. It is staggering when I travel from a urban area (expensive) to a rural area (extremely cheap). Take houses. Same house in a suburb might cost $500,000 vs. $100,000 in a rural area. Right there, that alone would make a sizable difference in someone's retirement dollars. And daily expenses there are less as well.
If I were retiring on a fixed income, I'd look at rural/middle America and buy a small house on some land, near a town large enough to support my needs, and within say 2 hours of a metro area (for airports, major needs, etc.). You can probably live very inexpensively and peacefully in such an environment while retaining valuable rights. Land would give you an opportunity to do some gardening (activity, lower stress, supplement food, eat better, supplement income with roadside sales), get some small livestock like chickens and such, maybe run a small side business making crafts and so forth, etc.