Having multiple sources of income is good but when there isn't stability of the outcome of income or wages at the end of the day, there is sure to be poverty and lack of financial power.
Therefore, do you think that a source of income must be steady enough for years, before one can be financially free or rich or very wealthy, depending on the source(s) of income?
You can be rich and never have to invest another penny again to make it last your whole lifetime, you just have to run the numbers. If you've got ten million dollars, you could spend $250,000 a year for 40 years before you run out of money - so if you retire at 60 there is a good chance you'd never need to risk anything again. You have to take inflation into account but even over that time period it is likely to last you, especially if you have already paid off things like the mortgage. However it is simply bad practice, because you can invest in index funds which might dip a bit during recessions but will grow back again afterwards and over the long turn give you 5%+ annual growth on your investment even if you stay conservative.