I make an unusual kind of art, but I haven't tried selling it, as you need a stable of interested people, and I can only post it in one place at the moment (a Facebook interest group on tiling, Instagram is overrun with AI, you can't start a new profile without lots of existing supporters). I've considered opening a gallery in my local area just to sell my art (5 million people in the metro, and barely a real commercial art gallery). My overhead would be just me and a location. The idea of selling art for tens or hundreds of thousands seems nuts.
I do see that there are too many galleries in places, selling too many artists, to too many people, with massive overhead (in the story, the gallery had $100k+ a month in expenses). Also, it's hard to make something new that is still saleable, almost every kind of art is basically something people did 50 or even 100 years ago; I look at art people are selling all the time, and most is not anything different. The best stuff is from people that hardly anyone knows, who like me just make something different because they want to.
I'd love to sell it online, but without an audience, no one will visit. I could sell it at https://www.saatchiart.com, but they don't really market most of what they have. You have to drag people there. Plus they take 30% or 40% (50% is normal for galleries). Locally, in the right location, people see your art, and stop by. It's just the pain of setting it up, and then sitting there while you wait!
Mentioned it here before, https://andrewwulf.com if interested.