Best way for steady income is having a stable job. I think there is no steady way to earn other than that. Having a job means fixed salary. Other ways to earn like having a business of restaurant doesn't give a steady income everyday.
That seems legit, stable job = stable income/salary. Of course, how can you have a stable income if you don't have stable job, maybe you should distinguish the ways of getting your profit. And with having your own business that is the only alternative way of getting good source of income, stable and own business = stable profit.
His business is very difficult to organize. This requires investment, not everyone they are in stock. I think that you should always strive to get passive income.