Anyone with level 20+ in arena 6 is a bot. Can’t get legendaries unless you’re extremely lucky, play entire days or straight up pay for incubators, let alone level 20+ legendaries.
Top 100 is filled with various players who own a legendary. I have the spino gen 2 from an epic incubator. Only seen regular spino in the wild, not the epic one. Every dinosaur is obtainable; just requires quite some time. Especially legendaries.
Concentrate on what matters: upgrade your common / rare team to 20 for ‘easy’ battles in arena. Next up are epics, which can take quite some time. Legendaries are way out unless… Read first paragraph haha. I’ve been playing since beta started - minimum 2h a day, almost got my first epic to level 15, maybe 2 are also level 14 but all others are 13 or less.
If you really want loads of new creatures find carnivore regions. Herbivore regions (mostly rural areas) have 0 new dinosaurs; okay beside the new common crocodile. I saw certain new dinosaurs in carnivore regions (more busy areas; city,…) but even then im highly convinced loads of them are still locked in the incubators.