Late to this discussion, but refer to this page and the next two after it.
http://www.mangastream.to/naruto-chapter-206-page-5.htmlKimimaro literally pushes the bone out through his skin and muscles, which become totally exposed, and then grabs it. After he takes it out, it all closes back up like it was nothing. That is some serious healing ability that the Kaguyas inherently have. The anime doesn't do showing it justice, since it had to be censored to show only black holes opening up with bones coming out. But when you get down to it, this is probably on par with Hashirama's Healing Power. And the only instance of that power which we refer to all the time is Madara's use of it while under the influence of Senjutsu Chakra. If we're going by resets, then 4 Senju and 6 Sage Mode resets are required to be on-par with 2 Kaguya resets.
And let's not get into the discussion of bacterial and viral infection. Unless someone wants to actually kill-off their character on purpose, people aren't going to die from those, unless it's done by an opposing party that had created a virus via their medical knowledge. The only instances I've ever seen of that in active use is the Poison Mist technique.
So yeah, once again winning the genetic lottery grants you a plethora of advantages over the average mook. Tsunade had to dedicate her life to Medical Ninjutsu to develop a technique that heals her body rapidly, after storing chakra into her Byakugou. While the Kaguyas can just do it at will. It sounds unfair at first, but let's not forget that the Kaguyas aren't the only ones running around with genetic advantages. Sure it sounds OP to heal wounds at will, but that gets pretty hard to do when you're Amaterasu'ed. Or if you're bisected by a Susanoo blade. Getting crushed to a literal pulp by trees that can absorb chakra is also hard to recover from. You can't mold the chakra to regenerate your body either if your tenketsu are closed via Gentle Fist.
My point being, is that the average guy is going to have trouble. But the genetically-gifted are going to have a hard time taking each other down.