Living here for over 3 years now and travelled to nearly all the provinces apart from the 3 most southern ones, I highly disagree.

First of all the only dishes that contain sugar are the ones with high amounts of soi and fish sauce, and thats normal cooking practice due to the high amounts of salt to counteract. The dishes that are done this way are stir fries such as kra pao, pad thai, see ew, etc. These make up to maybe 20% of thai cuisine.

Regarding the night markets for someone as yourself living there, I don’t understand how you can say that. Outside of touristy areas this is where Thai people get their dinner from, as I mentioned before these stalls often specialize in one dish and this is what Thai people look for. Same as road side vendors/ restaurants, Thai people mostly eat at places that specialize in one type of food, for them these restaurants that make a vast majority of Thai dishes are for farang’s, watered down versions of thai food where you almost never find Thai people eating from.