I usually don't give much thought to whether my virtual fantasy environments make sense, probably because they wouldn't really stand up to closer examination. Could a forest of this size really sustain that many wolves? Etc.
However, the situation in the jungles of Chult is particularly jarring. You can't take two steps without being assaulted by packs of predatory beasts, yet there isn't a single herbivore in sight. Whatever do all those raptors and tigers and tarantulas and giant scorpions even eat? Each other I guess.