A painting, if poorly executed, it should be qualified as "craft", and should be sold in a flea market or a garage sale. Today, the term "art" is too loosely used or better yet, misused. Especially by the so called "intellectuals" that qualify as art, anything they want. Who are they anyway? Most of them are not even artists.
If well executed, a painting should qualify as a piece of fine art, which silently speaks to your soul through creativity, contrast, color, light, textures, movement, and lots of good taste. If it fits this description, its monetary value over the years, should only go one way: UP.
A "painting" pleases your eyes, brings joy to your spirit, and gains artistic value while it beautifies a wall, a room, a home, a building or an outdoor space.
A good "painting" will speak for you, it'll tell the people about your refined taste. It'll flatter and bring you up to a category of a person with "culture".
Once hung, the painting is always visible to all but out of everybody's way; it doesn't make noise, doesn't smell bad, it's environmentally friendly, doesn't mind your yelling, doesn't require baby-sitting, or bathing, feeding, watering, gas, or batteries. It simply demands a light dusting every 6 months, and will be on this "cruise-control" for as long as you live. What could be better than a "Painting"?