Most of the older moka pots were made from aluminium, while some of the newer ones tend to have been made from stainless steel.
Re mugs, well, mine are porcelain or pottery, not stainless steel. This notion of traveling mugs is something that I have yet to make the acquaintance of. Likewise, I don't use stainless steel in either carafe form, or in flasks.
But you will have to prise my Italian Lagostina - or my German Fissler - stainless steel cookware from my cold dead hands......and, as for my Le Creuset (cast iron) cookware, or my Le Mauviel (copper, and stainless steel lined saucepans and casserole dishes), well, snigger, I daresay that they will find a use for years and years yet.