Well, at 50,000 I get another "dot" in my icon. Which confers upon me ... nothing except the extra dot and probably a congratulatory thread in the Water Cooler.
The only one that really matters is 8,000, which does have some real benefits, as you have discovered.
My wife and I play competitive Bridge. Some years ago we qualified as Life Masters. Both of us had the same reaction: "Wow, now we can play just for fun." It's the same here; now I can participate just for fun.