Most clubs have showers, free wifi, numerous power outlets, free snacks and adult beverages and, most importantly, a quiet place to relax before your flight (and none of those annoying "The TSA has recently blah blah blah blah" announcements over the PA). Many airlines offer reciprocal benefits with other airlines' lounges (for example, when flying on Alaska, you can use the Boardroom at an airport without an Admiral's Club).
Earlier this week I had to catch a flight departing at 6:15am. Instead of waking up at 3am, I spent my mandatory pre-flight airport time taking a shower (shampoo, soap, a razor and, of course, clean towels complements of the lounge), eating breakfast (free coffee, muffins and an apple) and catching up on email.
Even in the midst of his panic, Winston was too much taken aback to be able to hold his tongue.
'You can turn it off!' he said.
'Yes,' said O'Brien, 'we can turn it off. We have that privilege.'
Holy shit that is insane! Here in Australia I just get there 20 mins before take-off and pretty much walk straight onto the plane. They xray my hand-luggage and I walk through a metal detector on the way but that never takes more than a couple of minutes.
The only time where you might get away with arriving 20 minutes before take-off is if there's no security line and your gate's right near the entry to the departures lounge.
They do this because they know that people can be stuck for 30-60 minutes in a security line and customs & immigration on both sides add another layer of BS.
It turns 4 hours of round trip airtime into 8-10 hours of round trip travel time, starting from when you enter the airport. On top of that you have the stress of missing your flight because of this BS.