It only takes a few moments to find two suitable trees, and no ground clearing is necessary.
I've slept right over rockpiles and on 45° ridges before, and some folks have slept OVER a running stream!
For me, these things aren't an issue when I sleep in my hammock.
Since the hammock supports my whole body, instead of just an inflatable pad supporting my hips and shoulders, I don't get sore spots and it relieves the pressure on my lower back.
With my homemade hammocks without a fixed ridgeline, I like to have my hammock supports make about a 30° angle off horizontal.
If a hammock has a fixed ridgeline, the length will determine the level of sag.
While others are still clearing their tent site of rocks and roots, or trying to find a level spot, I can just string it up and stake out my tarp.For example, I often sleep about 45° onto my right side..quite a side sleeper, but not on my back, either.It's a very comfortable position that I can't get comfortable in if I'm on the ground.The hammock should have a fair amount of "sag" so it's not pulled tight.The amount of sag will vary by person and by hammock model.
It's the ultimate in Leave No Trace and stealth camping.