Oh don't me wrong. My leanings are towards they exist. Knowing the nature of how we exist here on earth. The probability of existence is greater by far than they don't.
Just by the shear fact that they exist in history in areas that we don't think inter mixed by shear distance. Kinda like herbs last longer in history than chemical drugs. Herbs have been in use for thousands of years. Those that don't don't last long. Pharmaceuticals are only around for a few years or a decade maybe two before they are withdrawn from the market.

This is because Herbs fairies and medicine are usually thought of as a part of the same picture. Another way is to say herbs, respect for the source of the medicine and the patient is. When we loose respect which is some of what the myth of fairies is about. Not they existence but they are perceived to be here to protect the herb. I you have the sensitivity to hear the plants need than you are likely to have the same respect for the pt.

Fairies were about helping the plants to thrive and protect them from their enemies. Which could be anything that could harm the plant. Foragers , insect, animal , other plants, and humans. They qualities represent exist in us all and can be cultivated.