You don't need a steady income to invest in bitcoin, there is a difference between having a source of income and having a steady source of income, steady means at a regular interval and there are many bitcoin investor who don't receive funds at such regular intervals, what's needed to invest in bitcoin is a discretionary income which is what's left behind after all you basic bills have been taken care of, you might be recieving money weekly or monthly, your source of income might not be steady at all like how it is for most contractors, just because their income isn't steady doesn't mean they don't have a source of income at all, so please don't misunderstand the two.
The point is that there are some people whose income is not steady. In fact, the amount of money they receive once in a while maybe after three months or twice a year—could be more than what those with steady incomes make in two years or more. So, as long as someone has discretionary funds, they can invest in Bitcoin. The point is that having a steady source of income is not a requirement to invest in Bitcoin. In fact, some people may have a steady income, but it’s very possible they don’t have discretionary funds because their income, despite being steady, is not always enough to solve their problems. So, this kind of person may not be able to invest in Bitcoin. It’s not just about having a steady source of income.