I left the UK in 2004. There are jobs currently advertised that pay the same, or in some cases 10% less, than I was earning then. Add even a very small amount of inflation and this makes for a huge drop in spending power. The average salary that people talk about in Japan today is the same as when I first visited Japan in 2005. I saw hourly rates in Portugal, where I first taught, a decade later that were the same as when I left.
When I first taught, there was no internet, no mobile phones and flights were expensive. I have since lived in places far more different and remote that were closer to home. When I started, salaries were reasonable- they had to be. Now there is a race to the bottom, and the starter ESL teacher will be paid far less than before. There are still opportunities for specialists, but ESL is a far less valuable profession today than when I started out and that race to the bottom is only likely to get worse.