(1) The Impressionists were furthering the project of the Realists, led by Gustave Courbet and the painters of the Barbizon School. Real subjects like everyday people in everyday situations were important to these painters. Landscape was important. Whatever was natural, just as it is, was important. Equally important was representing them with a sense of reality and immediacy.
Furthermore, in the 1850s, scientific studies had found this gap between the sensation of light on the retina and the appearance in the mind of the image, and then between that mental image and the significance or naming of that image. Monet and other painters were interested in that gap as a moment of bare reality.
Monet once advised another painter: "Do not paint a house, or a bridge or a tree. Paint only a square of blue, a smudge of yellow, an oblong of pink."
(2) As a practice of spiritual insight, the look of the painting matters not a whit. Working the painting into a work of art is another matter that develops in parallel to that of "seeing through the veil" of appearances. Making a work of art depends on knowledge and skill in manipulating materials and colors. It is possible to do both.