Why? Partly because in my formative years a badger sat upon my face and I found the experience to be hugely enjoyable, but mostly because there are three principle benefits: A richer lather is created, the brush exfoliates the skin and it lifts follicles away from the face allowing for a more even shave.
In addition, a good shave is a sensual delight. My friend James, whom I care for dearly, only dry shaves and it annoys me intensely. Much like Nazism or obesity. Why forgo such a delicious pleasure? Some plea there is not enough time. This is bilge of the highest order. If a gentleman can’t set aside a quarter of an hour to indulge himself (steady on) I think a severe readjustment of priorities is in order.
Like many boys I first became aware of the basics whilst watching my father shave, talking to him whilst perched on the edge of the bathtub. For those who are used to dry shaving (HEATHENS!) or others needing guidance have a gander at the advice proffered by the gurus of Geo F. Trumper.
Choose to wet shave with a good brush.
The best a toad can get.