No no you did not confuse me this is exactly what I mean, the CEX competitions where you have to trade as much as possible, the biggest turnovers win. Those are rigged, you lose on commissions and fees every time turnover, so you actually have to be very profitable on trades just to pay for fees.
What about on a DEX? They don't have such competition? But I remember Pancakeswap does really have a competition and it was a DEX. It is only up to the user's preference if what they will choose. You mentioned turnover there. I usually heard that term in gambling but it's amazing that it also exists in trading as one of their mechanics to win the competition.
I remember there is also one that is based on the highest profit. There are different ways to pull up a competition and all are only depend on the owner. Competitions can be damaging in our balances, so it's better to not prioritize them especially if you are budget user. If in case we still win, well nice and that should only act as a bonus to us.