It saving billions isn’t argument against it being good for employees/most people. If say the government introduced a bill that required every company to send 5% of their money to Russia, fighting the hell out of that bill would save them billions and would be in line with what most Americans want. There are more realistic ones like pretty much every iteration of the kids online safety act.
It might be a good rule of thumb, but it definitely isn’t the only argument/proof needed.
When they’re really little, high contrast is more clear and theoretically more interesting. There’s a lot of black and white toys aimed at newborns for that reason.