Shooting a bow is not hard. while a cross bow is demeaned for not being hard enough.
(...continuing with the hijacked theme…)
The deer part is easy. Wait long enough for one to walk within range.
The range is about the same.
Still need a good shot angle.
A bow requires movement and muscle holding power. The longer the wait, the more likely for a poor hold and loss of accuracy.
If the deer doesn’t bolt on pulling back, it may go on alert to your movement. They usually do on me. The next unusual noise or visual, it bolts. Your target just moved.
A crossbow lets you draw long before the deer gets there. You can hold more accurately due to less muscle strain. Even better, a rest takes a lot of the variability out of it. Chances are your movement to sight your target was not noticed. The deer is not on alert. The first noise it hears is the release. Your target may not have moved before impact.
The hunter is a wildcard…
Which weapon has more chance for failure? It’s my opinion, that all else being equal, the xbow will be more accurate and less chance for a poor hit for most folks.
What is hard? Practicing and tuning. If a cross bow requires minimal practice and lets someone take the first deer they shoot at, well that seems like a victory for the herd numbers and image of hunters in general. Perhaps coyotes and other scavengers should be the ones complaining about xbows.
If killing a deer or animal is a justifiable act, the weapon should not matter. I am not including spear throwing or other reckless ones.