The answer from Google's point of view is for the Thai restaurant to pay more for the advert so they are at the top of the rankings.

When Google stopped putting a meaningful distinction between paid results and organic results that was a line for me. It's fine to have an adverts - you have to pay the bills but when the adverts become the results it's just pay to play rentseeking by Google and the product is now untrustworthy and on a downward spiral as a result. Amazon search results have taken a similar route, you can search for something specific and get something totally unsuitable as top result now.