In PA, we can only shoot one buck a year and we are not allowed to shoot spikes or forks. So we can't cull. I've seen drastic improvement from the 3 things we can do:
1.) improve nutrition
2.) keep doe numbers in check
3.) Let bucks mature
We used to think that PA could not produce bucks that you see in magazines. We thought it was impossible, like we had a different sub-species. But we were dead wrong. We just never saw a 5 or 6 year old buck that had a life of decent nutrition.
I wish I could take the me from the 20 years ago and show him the trail cam pictures from the me of today. Or even show him the bucks that we have shot over the last 10 years. The most fun is going to the butcher shop in gun season these days and checking out all the caped bucks that are destined for the taxidermist. Back in the day, there were hardly any. Every buck got the antlers sawed off for the $10 wooden plaque.
No culling done at all here. Just more mature bucks. A fully mature buck is going to be impressive in most places, regardless of culling practices. Besides, you can't control what the doe brings to the genetic equation.