@clacke It is still a state matter, but if any state doesn't set 21 as the minimum age for alcohol consumption, the federal government suspends highway funding. Since the highway system is big and expensive, they all comply.
@Ahuka For the ones thinking if it is worth reading a quote:
"But then Mark Zuckerberg and Meta got to work. After all, while most of us see social media addiction as a health crisis, for Meta it’s a business model."
And the article shows in a convincing way, why too much of something that can be a good thing may harm.