Whenever It’s a good apple year and I have plenty of cider I do a wild ferment with some of it. This year I had 20 gallons to work with so 5 gallons was wild. I literally put it in a fermenter with an airlock and left in my 55 degree cellar from late October until last week when I bottled it. Wild cider ages beautifully so I bottle condition it and leave it in my root cellar. I will save much of it for next fall. The rest of the cider I fermented in 5 gallon batches with commercial yeast (s04, us05, and 71b). I just used camden tablets to knock back the wild yeast. I kegged those three batches, one was a rose that I added crabapple juice to and back sweetened a little with apple juice concentrate, one I hopped in the keg with citra, and one I backsweetend with honey and blueberry juice.
I have literally made over a hundred gallons of cider without pasteurizing over the past ten years with only good results. I have had plenty of unpasteurized juice right from the press too. Unless you have an immune deficiency problem, pregnant etc. I think consuming a lot of unpasteurized cider, veggies from the garden that are merely rinsed of bigger soil particles and fermented veggies like Kim chi is great for us and more and more science is showing lack of this linked to obesity, diabetes, and more. So the question to ask might be is pasteurized cider bad for you? The answer might be yes in large quantities. It is another processed food.
BTW any yeast will ferment cider to dryness even with no wild yeast involved. It doesn’t have the unfermentable sugars malted grain does. The way to tell if the wild yeast took over is if it tastes and smells a bit funky, in a good way IMO.
I think the reason cider and mead can still seem sweet is a combination of mouthfeel, part of which is carbonation in cider, and our mind being fooled by the aroma and flavor of apple or honey.
If you find the tartness to be a bit much it’s very easy to backsweeten in a keg: add a can of apple juice concentrate or half a pound of honey and mix around. It will be too cold to ferment very quickly, just drink within a few weeks.