I am friends with a camgirl who is a prime example of this. In her case, she made a go of full-time camming, and thought she was doing well. What she didn't understand is that the site she worked for paid her as a contractor and withheld nothing. She never thought much about taxes, and all her previous jobs had withheld taxes, so she didn't pay quarterly estimated taxes. Last month, when she went to file her taxes, she realized she owed thousands. She has been struggling to pay this while other unexpected expenses mount (car repairs). She's struggling with the decision on whether to pay her taxes or her rent, and is about to become homeless.
The super irritating thing to me is that she had a gofundme setup for her friends and family to donate to help with her tax issue. The campaign was going well (close to 50% complete) but gofundme took it down and refunded all the donations. This was likely because they don't want to be associated with sex workers, and she apparently had a link to it from her cam-site page.