So far, I have found it to supplement what I get. It is not big by any means, but the speculation and holding can be exciting. Waiting for the fork and the later or sooner
halvening will be another thing.
It is possible to make a living with just only Bitcoin but for that to happen you will need allot of Bitcoins to do so. If you do not make enough profit then it is not possible.
That is obvious, someone cannot make a living if he has no money and bitcoin is money as well, the more money you have the better your life style can be, so the more bitcoins you earn the easier it will be for you to make a better life for your loved ones.