Let's just say they split that €44k+ ($50,596 they make per month as of this post) evenly for arguments sake, they're each making €4,400+ a month, which is plenty enough for living expenses and possible travel costs depending, unless they're living in an expensive part of wherever it is they all live, they're getting a decent wage per month.
As a correction but to leave what I originally said here anyway, there's actually 7 people working on this game, so the amount they each earn, following the same split, is €5,700+ a month, so it's WAY more than what they'd need for living expenses.
Though really, money can't alter workflow (it can be an influence though of course) so maybe some of them are just slow are what they're doing or have overly complicated workflows. (which is a possibility as I know a few artists who have this problem)
But really we have no idea what's actually going on behind the scenes, we might think it's slow from an outside perspective but from their perspective, working on all of this, they might be working at a good pace or maybe even faster than they're expecting.
A cynical outlook is that they're fully aware the money they earn is going up gradually, so the longer they take to work on this, the more money they make per month, so it's better for them financially to not work as fast as they could in order to maximise the amount of money they're bringing in, there's no incentive for them to work super fast because their money is only ever increasing, but this is a cynical outlook and might not be the truth.