This doesn't hold in the age of slavery where you could get sold by the curt to slavery and serve on a galleon until you payed back your obligations.
Modern Capitalist workers actually have a very large spectrum they encompass, from very rich to very poor. Which is not totally unlike Athenian slaves, some of whom could become quite rich. But doubtless the modern worker has far more freedoms, and elects to restrict their life, in part due to institutionalized fear of no wages.