shock boots keep the shafts and o rings clean and have the action be consistent. The reason some buggies have them is because they have coated shack shafts. Take the eight for example, it has titanium nitride coated shock shafts so the boots keep the coating form wearing off.
if your shock shafts become scratched or pitted the shock will leak oil. Socks will also leak if the o rings are old/bad. Thats probably why you see oil on the bottom of your boots.
Titanium nitride coating is harder then the steal they used for the shaft. Its mainly used for its smooth coating which makes the shaft glide smoother
. the boots just keep the dirt at bay longer so your shock oil remains more consistent. Nothing like pouring out brown soup from the shocks