Basically, it was a giant rectangle, and the surrounding area was so dark people just ignored it.
the devs eventually separated the lower visitor center and the park due to performance issues, and people stopped visiting it.
But now the Lower Visitor Center has been completely revamped, currently being as realistic as ever.
But we have yet to see it in the new game, as they are still working on other parts of the map as well such as... The Gastric Seas, Amnotic Springs, northern bronchial forest, entry orifice and upper visitor center, and the left side of the map.
Of all of those things, the Lower Visitor Center, and Upper visitor center, entry orifice are the farthest ahead in development and will probably be added into the game within a time period of mid-2023-2024. (just a possible prediction)
Note from me: STOP BOTHERING THE DAMN DEVS ABOUT THE WILDLIFE PASS AND MOBILE PROBLEMS, THEY ARE TRYING THEIR BEST.
Thx, Owen Fritz <3