https://en.wikipedia.org/wiki/Decaffeination#Swiss_Water
Because GCE is saturated with the other water-soluble components of green coffee, only the caffeine molecules migrate to the GCE; the other water-soluble coffee elements are retained in the green coffee. The newly caffeine-rich GCE solution is then passed through the activated carbon filters to remove the caffeine again, and the process is repeated.
IDK. I don't particularly care what other people do with their pasttimes or pleasures. I enjoy and alcohol free beer every now and then, and if someone needs to avoid caffeine and wants to drink coffee, go for it.