I suspect that the added revenues this gave to Google were higher than the fine by a substantial margin.
There was a guy that was sentenced to 25 years in prison for stealing 2$ worth of pizza. If he was treated the same way as Google they would have fined him instead by asking he pay a 10 cent fine for that 2$ pizza.
No big surprise here, Google is part of the government surveillance state. I’m sure these child privacy violations will be turned over to CIA for use in the future.