They help a lot on varmint rifles, whether for coyotes, hogs or prairoe dogs, because they don't alarm multiple varmints nearly as much. I'm probably going to put one on some sort of varmint rifle soon, but probably not an AR, because the clatter of the action alerts animals far more than the report.
In other countries they're often considered polite, so are required for at least some hunting. We tend to think that other countries often have much stricter gun laws, but there aren't any of the fees and legal hoops for suppressors we have in either New Zealand or South Africa, two places I've seen them used, or even used them myself.
