Nah, those trading rewards are mostly being bagged by whales that have a substantial amount of funds to play around with, so shrimps like most of us cannot really compete against them and would just get rekd trying. So yes, its just a marketing strategy for projects and exchanges to get some exposure and hype, but small players in the space cannot profit off of it.
With a large capital and also has its own trading team, I think whales will always win prizes in the trading competition. But with a trading competition, we can test our trading skills and correct our shortcomings