How the funding works
A small amount is removed from qualifying pots in addition to normal rake and added to the jackpot pool. That pool grows until someone triggers it. In other words, players collectively pre-pay every jackpot ever awarded, plus the operator's share of the drop.
The honest way to evaluate a jackpot table is to compare the extra drop against the expected return from the pool. For most players at most stakes, the drop is a modest but real increase in the cost of playing.