I've read a few interesting responses here but they don't answer the question. I was married to a Thai for 15 years and, oddly enough, my fiancé is now also Thai. It is telling that despite a huge age gap between my ex and my new wife, both act the same. This goes for all 10 or so Thai females that I know relatively well. I believe I have a general answer to this question. I recently retired from work and reside permanently in Thailand. I still experience the same issues - and always have.
For background, Thais are generally absorbed with their appearances, saving face, looking good, wealthy and powerful. What happens behind closed doors is very different to the public personas that are acted out. Added to that, Thais have poor communication skills in their own language and they do not understand how westerners communicate or conduct business.
Having said that, here's an example: I went to a restaurant with my fiancé's family. I was asked numerous times during the day whether I'd like to go to a particular restaurant. But instead of taking me to my preferred restaurant as agreed, they took me to a seafood restaurant although they knew I didn't eat seafood. They assumed to order for me as my Thai is limited. Despite them making sure that seafood was not part of my dish, I was served pad Thai with shrimp. Instead of my wife speaking to the waitress, or even better, letting me communicate directly because I am an adult in my sixties, the whole family got involved. Everyone was talking, debating and then arguing with the waitress and then with one another. Everyone wanted to be the hero. At the time, I did not know what was said as my Thai is very limited. Thais don't like admitting to a mistake and it is not polite to lay blame. However, they all blamed it on the junior waitress from Laos because her Thai skills were not good. When everyone had finished debating, I then asked the head waitress whether she spoke English, and she said "yes". When I started explaining the matter calmly, my wife interrupted me and so did her family. They spoke over me because they had allegedly already explained to the waitress the situation. But I had no idea why my food was served with shrimp, what anyone said, whether I was getting a new dish or whether they wanted me to leave the restaurant? I am supposed to blindly rely on a bunch of squabbling people and just sit passively and follow their lead, or what?. After waiting for more than half an hour for my new dish, everyone had finished eating theirs, including deserts. Just as the dish arrived, I said "let's go" because my appetite had vanished. Now everyone got involved again asking why I wasn't hungry, whether I wanted another dish or whatever... The whole evening was a joke. I'm an adult in my sixties for crying out loud. The same when a different restaurant served green curry with pork blood. Sorry, not my thing. Instead of accepting that I'm not going to fish the pork globules out of the sauce for obvious reasons, everyone got involved again until I raised my voice and said: "There's only one person you need to ask what he wants - me. I've told my wife what I wanted - period. Live with it!".
The same when I went to buy a tablet for my wife. My daughter in law came with us. This purchase was meant to be personal. However, the daughter took over, she rushed us to her preferred shops and interrogated the sales people on our behalf - all in Thai. I was just a distraction. When it was all over, my wife finally asked "which one do you want to buy me?". I told her to ask her daughter. After some discussions and paying for the tablet, my wife asked what was the matter? I told her that all I did was pay for the bloody thing. This was a gift from me to her and that I should have been involved in all aspects of the purchase and not just present my credit card.
Whether it's a car or a house, everyone wants to help. Why don't you move here? Why don't you move there? Why do you want to buy an EV? Why a BYD? Why, why, why..?
The same with all other purchases or decisions. Buying a car, a property etc. they don't understand that although I have no rights under Thai law, the fact that I am here and forking out big money means that I should at least get courtesy, respect, you know, the stuff our grandparents tried to teach us? In fact, if I were an old Thai man, there would be no interruptions. Thai society is obviously so focused on themselves, their plight and how appearances will affect THEM that they ignore you until there's a bill to pay. A farang is only as good as long as he spits out money...
I wish I was wrong about this but that's over twenty years of experience and analysing Thais.