We entered Cambodia at poipet a week ago. Yes they take Thai baht. 1300 is what they wanted. A bit more than $30 but OK. Food and hotels at the border city also took Thai baht.
Yes, it is lack of understanding. Also, people on the street are not undergoing surgery by other people on the street. And the concern there is bacterial infection, not viral. It is well known that masks do not work for a virus, or this virus. You don't have to fear the air. Why do you fear the air?