More people playing (paying) does earn out the advance faster, but the advance is basically game theory.
The publisher wants it small, in case the game/book/whatever doesn’t sell, and the IP holder wants it big, for the same reason.
For most cases, like for a first-time author, the publisher usually holds the power. But that dynamic reverses when you have a big famous IP. The IP holder is incentivized to hold out for a big advance, only making it smaller if it risks not selling at all.