Thailand is a mixed bag, like almost anywhere, but if it stops being fun you more on.
I suspect for many as they age, the savings dwindling it gets a whole lot less 'fun'
Health can decline, and good luck getting health insurance at almost any price 65+, which means you're staring down a Government hospital, which outside of BKK can be pretty dire.
So what was fun, in your 40's and 50's can become pretty horrendous if you get down to counting pennies in your 60's, 70's and if it gets to it, tin roof shack in Isaan!
Then for some, I'll include myself, you just kinda bore of it.
Been There, Done That,Got Tee Shirt kinda moment.
Thailand is a little like Disneyland, but with hookers and a whole lot dirtier!