That's true. I remember the drinking age of 18 in NY, 21 elsewhere. I remember the fairly routine death crashes on US 17 in northern New Jersey, as the kids would drive up to NY on Saturday night and drive back blitzed.
The U.S. has a tortured history with drinking, with the Feds actually outlawing alcohol for twelve years - 1920 to 1932. The idea was well-intentioned. Drunk drivers, drunk at work, drunk in fights, drunk husbands beating wives, drunk people going bankrupt chasing demon alcohol, etc., would all be avoided because of Prohibition. But most people didn't like that law at all and had no problem breaking it. Prohibition didn't stop drinking but made it more socially cool, and running alcohol financed criminal enterprises that still exist today.
There are reasons to limit the use of guns. Sometimes the intentions are good. For example, most cities and towns say you cannot discharge a gun within City Limits (for purposes other than self-defense). I get that, its crowded here in suburbia and bullets that go up have to come down. Many concealed carry laws specify no guns at funerals or political rallies, because that's when people's emotions are high. A lot of state laws on concealed carry said no guns in bars, because alcohol and drink don't mix well, but some areas have backed down a bit and allow guns in places that serve drinks as long as the person with the gun isn't drinking. Cowboys were not allowed to have guns in Dodge City on Saturday night, we learned as kids watching TV, because they get in fights with each other. America got used to living without machine guns in the 1930's, after they were severely restricted because of over-use by gangsters during Prohibition (demon alcohol again). Handguns used to be for sale in hardware stores everywhere but now can only be purchased through FFLs. The no guns on commercial airliners law came into play after some folks used them to hijack airliners, so seem reasonable enough. On and on. Bans on black people owning or carrying handguns were egregious, a classic example of using gun laws to control someone's political enemies. Not letting 18-21 year olds buy handguns is not the worst gun control law I've ever heard - and we've been living with it for 55 years. At least they are allowed to have a shotgun. I don't see the latest court decision as being some sort of breakthrough for the RKBA.
The best anti-gun law I've heard is the ban on felons buying or possessing guns, but I could easily live with that law applying only to those convicted of violent felonies, and even for them I could live with a "earn it back" provision after 15 or 20 years of no further run-ins the law. Every time my mind wanders towards the idea that, "well, there must be some sort of reasonable gun control laws," I find the goal of most gun control laws these days is to annoy and punish law-abiding gun owners, and I find these gun control ideas to be the camel's nose under the tent flap, leading the way to more restrictive gun control provisions. One thing that bothers me today is the idea that restricting ownership of guns by law abiding citizens is the answer for the use of guns by criminals. It makes no sense.