I don't agree with the broker's role in trading.
The broker is the most important thing in trading because if a broker is a total scam, then whatever skills and knowledge you have, you'll not take any profits and lose your deposit. Brokers are mediators between traders and forex market. There are lots of things where they can cheat you. THe most obvious thing is that they will not allow you to withdraw the money. They can show you some beautiful numbers of 1000% profits within a week, but it is nothing more than just the numbers on the screen and these numbers can never be turned into the money.
Some scammed brokers cheat on traders providing them with wrong information about the asset prices. It usually happens when it comes about binary options when some traders trade within ultrashort timeframes, when every minor fluctuation matters. So, the scammer just draws some numbers which it is interested in and the majority of traders lose their money.
More than that, even trading with honest and decent brokers can give you no profits. For example, the charges may be so high that you'll give the biggest part of your profits to the broker having nothing to yourself.
Therefore, all of the traders should be very attentive while choosing a new broker to work with.