Stand-By Flights, Regardless of Destination? [duplicate]

I've started seeing commercials for some company doing a kind of "travel roulette" where a traveler is randomly given a destination and their vacation is free if they agree to go right now. Which is pretty cool, but the idea got me thinking...

If someone were to set up a general time slot (say, 2 weeks) and just show up at the airport (US in this case) with only a carry-on bag, is there some way to sort of hang around in a stand-by status and pick up a last-minute stand-by flight really cheap? Basically, not caring about where to go, just wanting to go on some sort of travel "adventure" somewhere in the world? (That is, this is specifically asking about international flights.)

I feel like that used to be possible back in the day, but I don't know much about the rules and regulations these days in US airports aside from just shuffling through like any other traveler. For example, one used to be able to get to the gates without a boarding pass (which I imagine would be the ideal place to grab a last-minute "the doors are closing now and there are still empty seats" ticket), but that's no longer the case.

For anybody who happens to work in or know about the workings of airline travel, is this something that's possible? It occurs to me that, at that last moment when the plane is boarding, any empty seat is essentially lost revenue. So I would think that there should be some way to get into one of those seats at cost plus a moderate fee. Or is this just wishful thinking? Even if it is possible, is it not worth it because getting back home would be cost-prohibitive?