30 acres isn't enough to hold multiple large mature bucks.
I agree its not.
Yes some deer in some developed areas stay their whole lives in small plots but that's not the case if they have other good feeding and cover areas close by.
. I'd say if you want to hunt your own deer without pressure from other hunters and have a choice of stands for wind direction and weather conditions and what not then you need at least 100 acres. And to my mind 100 acres is really just getting started.