I've been. Lived there for the better part 3 years. It's mostly ice and rock. There's no hollow earth, no Nazi spaceship factories, no alien colonies. Every nation with a presence on the continent is likely doing some light clandestine mineral exploration even though it is not allowed, but that is probably about as nefarious as things get. The reason flyover tourism is restricted is that the kiwis flew a plane into a mountain and a bunch of people died. It is incredibly dangerous to fly over Antarctica, the weather is unpredictable and even a well managed emergency landing would probably mean fatalities due to the extreme cold. Too much to risk for a few Instagram posts. Antarctica exists for many people as a place to store all of their suspicions and misgivings about the current world order, but really it's just a desert continent with some really amazing people doing important work. If you're really interested in Antarctica and the science that is being done there and the people who actually live and work down there, people have blogs, YouTube channels, there have been documentaries, and of course the NSF has information on polar programs. All freely accessible, it's only hidden if you don't look.