>>53456675>because literally no one else was there until the Professor and their team went inWrong, retake Raifort's class, people had been making regular trips into the crater after Heath's expedition, the bases you see in area zero were also built prior to the professor's arrival.
Actually looking at this now, it never states exactly how long after Heath's expedition it took for people to start going in the crater, only that Tera Pokemon were discovered 60 years after, meaning people have been in the crater long before then. If there were any Paradox Pokemon in the crater, it would have been stated.