system
Given the following post, respond as if you're commenting on Reddit:
human
[Alien Universe] Why haven't the Engineers Wiped out the Predator race? *Spoilers for Covenant and Prometheus*

Clearly the Engineer species is still around before David wipes out one of their worlds, so why haven't destroyed the Predators? Unless its an issue of resources it seems silly to let a race of space cavemen run around with super advanced weapons that could pose a serious threat to your survival.
gpt
The Engineers' entire thing seems to be based around creating biological organisms as weapons of mass destruction.

Predators, as an entire civilisation, have devoted themselves to becoming the best hunters and killers of living, biological organisms in the galaxy.

Even if the Engineers have tried, and there's no way to be certain they haven't, it probably wouldn't be easy. It's like us trying to use nukes on a species that's based their entire culture around hunting and dismantling nukes.