Originally Posted by TravelStar

The first Centurion lounge opened in Las Vegas in 2013 and was initially pay for entry for any but Centurion Cardmembers. Here's a quote when the Las Vegas lounge first opened:

"Any eligible American Express Cardmember may purchase a one-day Access Key at the Lounge for $50. If you hold a Centurion Card from American Express, or if you received a promotional mailing with an Access Key, access to The Centurion Lounge is complimentary. Purchase of one-day Access Keys is subject to Lounge capacity."

The Platinum Card annual fee was increased to $450 in 2007. Long before the Centurion Clubs were an idea much less a Platinum benefit.

The lounges were never built or intended to have the type of volume they're seeing. Most have reached capacity and are turning people away at peak times.