Millions of members that have joined WGT since it started in 2008.
Most of those millions are no longer active. Currently active is a much smaller number, and active right now likely means some 10's of thousands.
You can only 'join a game' that hasn't yet started.
At any given time up to 98% of those wanting to play have already started a game.
A better approach is to be the one that creates a game rather than joining a game someone else created. That way you get to choose the golf course and what range of tier levels you are willing play with.
I too am a Legend, and I set the Player Invite to Tour Pro and up when I Create a Game.