Then again...... I've been to Grand Cayman seven times and it was never bypassed. It is somewhat the luck of the draw and the vast majority of cruises don't bypass Grand Cayman.
If you haven't done Stingray City I suggest you give it a try. It is fun to do.
Seven Mile Beach is fun for just a beach day. You can also go to Hell.
It's a small rock outcropping on the island and it has a post office and souvenir shop so you can send a "Postcard From Hell". I personally found Hell a bit underwhelming.
My brother did the Atlantis Submarine and enjoyed that.
So there are a number of things to do.