In my opinion, they would kill more deer because they would not be competing with my baiting - and most would be young bucks or does. Each one of my feeders has a large doe group that locates their home range around one of my feeders. One had 12 does and fawns - the other two have fewer - from four to six. I believe the feeders keep the does on my property more where they are less likely to get run over by cars, fawns are less likely to be killed during hay season, they are less likely to get poached, etc.
About 12 years ago, my sept cam survey showed six adult does. I invited the state head deer bio, asst state deer bio, and the area bio to my land for a ride around. I had been whining and griping to them for several years to reduce the doe harvest. Grilled them some burgers and we took a ride around. Almost untouched soybean plants, little to no browsing on preferred deer plants. At the end of the day, they all agreed I had a noticeable lack of deer - but in the end, they said they could not manage every corner of every county.
That is when I decided if I wanted deer, I waa going to have to do it myself. First thing we did was immediately stopped killing does. Did not kill one for eight years. Not even the 8 yr old grand daughters. A year or two after that, we started putting out a couple bait piles for the grand daughters to hunt. I noticed that the more consistently I provided supplemental feed, the more my does were seen in the area. I even had an adjacent landowner tell me he wasn't consistently seeing nearly as many deer at his feeder as normal. I didnt tell him, but I was seeing a lot more deer on my place.
None of my neighbors feed outside of hunting season. I provide high protein, high fat feed for my does all summer and corn the rest of the year. I would do this if a buck never showed up at supplemental feed. I want healthy does, that stay on my property a lot, and produce a good crop of fawns. I now normally have about 30 adult does on my camera surveys - up from six.
Interestingly, even when I only had six does on camera survey, I had quite a few bucks - usually around 15. My theory is the bucks moved to my place because of the food plots and it became their home range. They did not stay around during season - I think they bred the few does and headed out looking for greener pastures. Now, I usually have around 20 bucks and many of them stay here year round.
I have a spinnfeeder 400 yards from the house, on the edge of a 2 acre food plot and fifty fruit trees. There is a doe herd there, that we see almost daily. There are a couple does we can identify - one because of a limp - who has lived in that area for at least six years. On average, this doe group gains one deer a year. Before season, they were up to 12 in number. I am not sure how many are still in the doe group - they left the feeder three weeks ago and are in the woods eating acorns.
I know this is a long answer for a short question. I am fortunate to be retired and live on my property. I have killed one deer in the past six years and did not kill it on my property. I live for this stuff. Not many days out of the year I dont do something to maintain or improve my property.