And yes, you can access as much of Antarctica as you wish (except for the 2'ish percent that you would need a permit for scientific research). There is no one keeping you from doing that. However, it's a dangerous place. No one is going to just go on a whim.
I wrote an article debunking that too. There is only 2% of Antarctica that you need a permit to access. No different than many National Parks. I needed a permit to camp in the back country of Yosemite, or to climb to the top of Mt. Whitney.
There is zero evidence that anyone would stop you from doing an Antarctic expedition if you wished to do so. But it's a harsh place that scientific teams have even had to be rescued. A recent article where a scientific team was rescued talked about the incredible hazards of the people doing the rescuing!
I've asked for people to provide me evidence of anyone having been stopped who tried to go to Antarctica, and there is none. Have them show you a video of someone being stopped by the UN in Antarctica. It simply doesn't exist. But you will find a few articles and videos of solo explorers going across antarctica, and many scientific teams on many different scientific research stations.
RE: Flat earth - the beginning of my research