Games sold for the most part. Baldur's Gate 1 sold 2.2 million copies over 5 years, Baldur's Gate 3 sold that during early access and over 10 million in less than a year. First Call of Duty sold 5 millions while the newer ones sell 30 millions. OG resident evil 2.7 million, newest resident evil 10 millions.

Once you've made a game the cost of producing another copy is pretty much just the cost of the physical disk and shipping and distribution. Like the biggest cost is labor from developers but once it's made you can and should makes as many copies as possible.