Trading competitions are suitable for highly active traders with considerable skills and substantial funds, as capital is key to winning in trading competitions. Exchanges typically consider trading volume, and some also calculate profits over a specified period.
I've done this before and managed to win one of the prizes, but it was significantly lower than the prizes for the top prizes, the trading volume is significantly different, so substantial capital is also required.
To be fair if you are a professional trader, literally someone who does this as a job, then yeah you are going to benefit from it a lot. But most people are not, and they do not get that type of return, so it is not smart for them to use it. Many who do not trade that much per day, end up joining just to see, and they end up losing money and winning nothing.
If you want to win something and be good, then you need to be a good trader before the competition starts. Obviously some newbies could get lucky once or twice, but they are not going to have the long term benefit of it, and will not be getting advantage, so I highly suggest not getting that kind of return, because it is not going to benefit you right away.