As has been said, Upwork and Elance are very often a race to the bottom as far as rate is concerned. (BTW, Upwork owns Elance and is in the process of shutting it down so I would not focus on Elance at all.) I have used Elance to round out my portfolio, allowing me to take on projects in areas that I wanted to build experience. Thought the rates were lower, I have been compensated for essentially learning. I have also made a few contacts that have lead to better opportunities.

Three things I recommend:
(1) Use Upwork to build your portfolio while earning some income.
(2) Differentiate yourself as much as possible - I have gotten a more premium rate by demonstrating a better ability to deliver and higher quality. (Many people have had bad experiences with lower cost labor and are looking for a better option.)
(3) Take time to build relationships with customers. It will often lead to a greater opportunity.