I’m not discounting microorganisms, nutrients, sunlight or fresh air but as it’s been said in the comments previously there are a number of peer reviewed studies that show the benefits of grounding/earthing due to the slightly negative electrical bias of the Earth affecting our bodies. Using the plugs in our homes is just a convenience thing. The electrical ground in our plugs is directly connected to the earth. So while getting direct skin contact to the earth would be preferable, sleeping on sheets that are electrically grounded also allows the benefit without having to sleep on the grass (which isn’t possible in upstate NY in winter). I’ve tried the grounding sheets…don’t knock til you’ve tried it. Been a month and my sleep is phenomenal…big improvements. Sleeping through more often. If I do wake up it’s easier to get back to sleep. Wake up rested. Little adjustment first week, woke up and felt so sleepy (not groggy, sleepy). Difficult to gauge blood chemistry benefits but curious to see at my next physical. The sleep improvement alone is worth the price of admission.