The boycott of the gods has reduced the rate of accumulating divinity, but it hasn't made them helpless. Their immense Authority has come to their rescue again. With 673,891 believers producing an average of 1 prayer per day, they can produce 6,740 divinity as long as they have divine crystals.
That's the equivalent of killing two gods with 6,740 per day. They can produce 2,460,100 in a year. After they pay their 100 divinity per day rent, they will still have 2,423,600 in a year.
So in time, their storage of Authority will become terrifying. Their increasing Authority will make that day come sooner.
Fortunately, they don't have to wait that long. The opportunity has come for them to fix the problem quickly. The gods desperation to acquire the Authority of the void has overcome their fear of the Orc Bandits. It is like Legion-3 said, they will be able to eat well again.