Side note -
As you can earn up to 108K USD, tax free as an expat (more, much more, with a good accountant) , doubt that is a real valid reason. Lots of people like to talk about, cry about, get outraged about, the IRS. People I have met with real IRS tax problems living over here, invariably incurred them because of businesses, real estate, previous ownerships, earnings and how to say, 'legal judgements', all from their time in the US. Not from living and working overseas.
You are spot on about the distance time equation. With a 16 to 24 hours flying time, once you factor in airport and change flight times, that is one long painful trip. Given times zones, one of the worst jet lags you will ever encounter., coming and going. All for a two or three week vacation?! Thailand will always have US tourists, but not enough to be a major player. That said Thailand was getting more US retirees in the last decade, likely for the same reasons they had previous waves of Germans or Brits. All that before the pandemic though, who knows what will happen now.