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?
Richness is not about having multiple sources of income but having a steady satisfactory inflows of continues actualization of the income.
You can not even say you have acquired financial freedom when your income has not been able to afford your needs and response to your financial responsibilities.
One source of lucrative and productive income is far better than a hundred sources of dormant sources of income that is not meeting up with your financial expectations.