It does say that right on the frontpage of the pool (the APR number)? And if you click on the pool you want to deposit in, it’ll show a detailed table (Pool’s stats) for how much POOL is dripped to the participants.
If you just remove the lottery award and distribute to the people who play, then you are basically a front for compound (or other yield sources) and not a lottery anymore. That defeats the whole purpose of this project. If you are interested in reading more, there is a whole discussion going on with respect to how to optimize and grow the prizes you can win as a lottery participant through the introduction of a reserve rate.
But you are right that at the moment, gas costs are simply too high for small deposits to yield a decent return.