This notion is far removed from reality and in fact technique and method have been very important at any point in art, or at the very least in their consideration as art today.
These blots are less present in the immediate foreground of the work, but they possess the striking characteristic that in some places they lose nearly all direct reference when viewed up close.
It could have been argued that the exact shape of the brushstrokes are an quasi-accident or a mere byproduct of the material available to him.
Yet it seems to be a clearly defined choice of technique, rather than a shortcoming of any available materials. In the detail below from Metsu's earlier painting, each ball on the dog's collar is about the size of the dog in Vermeer's painting, clearly demonstrating that smaller and more accurate details have been achieved by other painters with access to similar materials.
By comparing these three artists and seeing that although they worked during a similar time and in a similar place, they have very different and distinct approaches to how one creates a painting. It is thus clear that they did not all aim at the same singular outcome, but rather searched for innovative technical solutions and that their different outcomes were not limitations in achieving perfection, but rather deliberate choices that defined their respective approaches.