Of a truth, no matter how much anyone may earn from a single income source it would never be enough to cover his overall needs and responsibilities but having to create other income sources with time will help minimise if not completely eliminate such insufficiency as it were. Additionally, having to live a life of modesty can be so beneficial and peaceful than anything in the world. Often times why we see people that earns so much but still living in debts is as a result of not living modest but overly flowery lifestyle. People with such lifestyles hardly make room for savings or investments, which is a life not worth living.
Some of my colleagues who earn far higher than me are deeply indebted. Some of them are in that situation because they spend more than they earn. I am not in by any means against living a good life but it should be done based on my own income. Spending so much money on things that one can live without is unnecessary especially when you don't have enough money to waste. They have mocked me for not buying expensive clothing or living in a highbrow area, but the good news is that I am not indebted and I am also investing for the future.