Can hair treatments stimulate new hair growth in areas where hair follicles are completely dead (bare, shiny skin)?

No, this is medically impossible, and realistic expectations should be maintained. For all clinical treatments like hair mesotherapy, PRP, or laser hair removal to be effective, there must be a hair follicle that is still “alive but weakened and miniaturized” (turned into a fine downy hair), where cell production hasn’t completely stopped. If the scalp has become completely smooth and has a shiny, marble-like appearance, this indicates that the hair follicles have completely disappeared and been replaced by fibrotic connective tissue. No amount of vitamins or lasers can revive a dead root; at this stage, the only definitive solution is a hair transplant operation.