If you can earn money and make a living in general then you should be able to do the same with bitcoin.
The only difference really is the payment method and as bitcoin becomes more widespread and used, the time will come that most people will pay or get paid in it.
Yes that might happen. I have friends like single mothers who are working at home and they are still paid in US dollars. It is an online work so maybe someday they will also be changed to a bitcoin payment if they prefer it.
There are already a lot of opportunities online just waiting to be discovered. We know a lot of people who just work from home and earn big amounts with their online jobs. These earnings can then be used to buy bitcoin.