Coping with one source of income is possible depending if you are single and you have a good job that earn you better salary and you can minimize your spending

But coping with one source of income when you are a family man is not possible
Imagine if you are a family man with two kids or more and your wife that is family of 4 you pay your kids school fees you pay water bill electricity bill and all the rest it will be hard to survive with one source of income and  the average family don’t need to have one source of income

Price of things are increasing everyday and one has only one source of income with family of 4 your salary will be from hand to mouth and at times your will always live on debts once you get your salary you pay debts

But if your source of income is from crypto currency I think one can live with one source of income if you a good trader and a good bitcoin holder who know what he or she is doing