The word “art” can cover so many facets of creativity worldwide. To pin it down to one single area would be an exercise in futility. As far as niches are concerned, there aren’t as many that are profitable as you would think.
This major category includes the following subcategories. Although these subcategories can be profitable for some people, I don’t have any experience with these specifically, except for two related to art class in school, drawing (or sketching) and painting.
I’m not being paid to promote this, but I found this Fantasy Art Investment Guide. It calls the originals of the images fine art.
Art class is usually an elective in an American high school. It was for me, back in the mid-70s. It was only a semester, but I learned more about water colors, screen printing and sketching than I care to remember. As far as painting is concerned, I probably learned more from Bob Ross and his happy little trees on PBS than that class.
At home, in the mid-70s, I probably spent way more time sketching nonsense than I should have. I never got very good at and I could never do hands and feet correctly. I tried copying comic book characters freehand (no tracing in any way) but I grew tired of it.
I have a lot of other kinds of talent, but “art” isn’t one of them. I have a nephew on my side of the family, however, who publishes his own comic book line. It’s been years since I talked to him and I rarely converse by text with his siblings or mother. I only know about his artistic talent because of what I’ve seen on Facebook.
I have a niece on my side of the family who does artwork, but I don’t follow her on any social media. It’s been at least 20 years since I’ve seen her in person. As far as I know, my wife, Josie, doesn’t have any artistic relatives on her side of the family at all.