The regular use of lemon and/or overuse of lemon water
dries out the throat, alters the delicate microbiome in the
mouth, and removes the moisture on the surface of the
tongue that’s necessary for proper taste.

Because the dominant tastes of lemon, according to Ayurvedic medicine and Traditional Chinese Medicine, are “sour, astringent and bitter” (as seen in the preceding screenshot), this citrus fruit can have a super-drying effect in the mouth and on the throat.  This triple whammy of a drying agent is explained as follows in descending order.