The lottery’s and retailers’ profits are each a fixed amount of the ticket price, and the rest goes into the prize pool. They don’t lose any money unless they commit to paying more prize money than they allocated to the pool. Jackpots are explicitly a (large) fraction of the unallocated award funds and so cannot make the lottery operation insolvent— only an excess of fixed-value awards can do that. In fact, the increased sales on rolldown draws just mean more profit for the operators and reduce their biggest risk, which is something happening to the stored funds used to pay out prizes.
