1) venue is in meatspace, 2) age can be eyeballed, 3) they don't routinely hoard data, 4) they don't routinely leak hoarded data, 5) they aren't monopoly with billions of users routinely extorted for PII, 6) they don't routinely leak all that hoarded data, 7) they don't have bots, 8) they aren't connected to PRISM for routine surveillance, 9) they don't routinely leak all the hoarded data, 10) they don't sell hoarded data on black market, 11) they don't sell hoarded data to thousands of business partners, 12) they don't have thousands business partners that routinely hoard, leak and resell data

Maybe that's why metabase was hacked - to conceal sale of data. "It's just a hack, it happens, we fixed the hole, nothing to see here until we find the next buyer".

Because otherwise they can not serve alcohol. This is the law because alcohol is an addictive substance and more addictive if interacted with in younger years as your brain is not fully developed. And "we" as a society deem alcohol consumption problematic as it is associated with risks for other societal participants, like drunk driving accidents and domestic violence. Similarly why you can't enter a casino underage.

The underage crowd can't enter a space that is specifically exists for experiencing the prohibited behavior. Where the internet is a more general space and we are restricting anyone that has not proven to be adult. And what are we restricting them from? Posting/publishing & accessing content, that sounds like age based censorship.

Would someone underage have less rights to receive or publish unpleasant/controversial topics under the First Amendment? I think you need to have a very strong case to undermine those rights and I just don't think "might protect the kids" (which is debatable) is strong enough.