Short stories don't make a lot of money. $100 is a huge accomplishment. The goal is usually to have them spike sales for a novel, but even there (a) it's iffy, and (b) most novels only sell a couple thousand copies.
Writing, unfortunately, remains something you have to get financially comfortable to be able to do... not a way to become financially comfortable. It's surprising that even in 2022 we haven't fixed that.