Hi all,
However, it seems that most of the competitors are professionally trained musicians who cannot make to the real music world so that they do something else for a living.

Uh, no. Most of them are people who have had very good training, and have been dedicated, but have decided to persue something else as an avocation. Lots of them could have made it as professionals if that's what they wanted.
As far as amateur competitions, there are lots of them around.