Population decline is a huge problem for inflation and for getting services. It can spiral things out of control in a big hurry.
The thing that makes me chuckle is that this has been on people's radar for nearly 40 years and first world nations have been actively increasing immigration to cope with the shortfall. Less people, less taxes, less businesses, etc etc etc.
AS usual, poorly run nations, like poorly run companies end up at the back of the line. Companies end up bankrupt and Thailand,, if it continues to act like a third world nation in a broad sense, will continue on its slide downward to third world status.
This is what corruption does. It's a cancer. People who have no business being in places where they should don't look out for anything other than short term selfish gains.