It isn't just Thailand, it's happening everywhere.
In the West we are in a permanent emergency/crisis (covid, war, climate). People are scared and getting poorer (the middle class is being destroyed).
Thailand has been affected by the covid pandemic only and some inflation due to covid and the war. But I'd say that the West is in a much worse condition. Economically and socially.
I find the people here to still be friendly and smiling, but less than before. The occasional 'hate you look' didn't happen before. And they are direct on money more than before.
Jm2cent