It doesn't take long in Thailand, when looking at those businesses which employ people who are visible to the public, to see how often there are many more people employed than need to be. Whether that is in a shop, a restaurant, or a building site, there are typically more people than are needed to complete whatever task it is that is being done.
I suppose we don't truly know if the employer is employing that many people because they like to have a buffer of bodies in case things get busy, they feel it is their civic duty to employ as many people as they can afford to, or if they simply view that as the norm.
It's quite likely, though, that if wages should double overnight, they might think about downsizing their workforce, since, to most, they appear to have an excess of employees.