See the interesting thing is African megafauna evolved to be able to somewhat counterplay this, that's why they ain't extinct like megafauna everywhere else ended up going.
The horse was indigenous to North America before it was hunted to extinction there, making the age of exploration inadvertently one of the first ever native species repopulation projects.
Too small at the time, it took a concerted breeding program for ancient steppe peoples to first breed horses able to pull chariots, and then big enough to be ridden.
Humans have been migrating over the world for tens of thousands of years and yet the horse was first able to be used for transportation about 4 thousand years ago.
Been reading the "Deathworlders" novel. Earth is a Level-12 "deathworld". Too impossibly dangerous for sentient life to evolve on a Level-10. Gravity, parasites, bacteria, fungi, viruses, predators, solar radiation, extreme heat and cold, tectonic activity, tornadoes, hurricanes, all that.
Rest of the galaxy wrote us off as too dangerous to even investigate. And besides, there can't be intelligent life there.
Free book, kinda like a FOSS story, if you will, but not fan fiction either. Getting a little odd several thousand pages in, but I'm hanging in for the last 800 pages (out of 10,000+).
Google "humans fuck yeah" or "HFY" for more fiction along these lines.