It's a real tricky problem. In most places, humans (via hunting, but also car) are the only predators for deer, so if humans stop hunting them, the problem only gets worse.
The solution is also not reintroducing predators like some of the anti-hunting crowd would have you believe: you aren't going to get a stable wolf pack in suburban Pennsylvania.
The best solution is probably a radical shift in hunting legislation. Many regulations exist simply to make hunting more difficult. Some regulations, like the existence of hunting seasons were useful before technology to monitor populations really existed, but now we have trail cams, aerial surveys, harvest reporting on phone apps, etc.
It's easier to take a rifle and go harvest a deer in supposedly gun-averse Australia than it is in most of the places people live in America.
We also need easy, free CWD testing.