I can only speak to my own interpretations of the text, but this is a setting where magic well and truly exists, if typically in forms that were seldom seen directly. I don't think it's explicitly said, but again, Bilbo the burglar and Frodo somehow sneaking into Mordor, there is a broader underlying implication that hobbits are intrinsically easy to ignore and discount. I was always given the impression this was largely what kept them safe, not any realistic defense mechanism, but a borderline mystical unimportance.