This is what attracted me to the side hustle in the first place, although it is a bit of an illusion. To build sufficient cash flow from this side hustle reliably every month, you will inevitably have to take on work that doesn't excite you. It's also relatively easy to become "too good" at this line of work, and having people constantly "persuading" you to take on assignments that you don't have much interest or skill in, but you do it anyway to keep them happy so you can keep the cash coming in.
Definitely good in a pinch, but I stayed too long, and I am very happy to have gotten out!