That's simply not true though. You can definitely say "who dares [insert verb without 'to']" even if it sounds archaic. "Who dares disturb/wake me?", "Who dares utter my name?" a.s.o.
We would generally say: "How dare you say that to me!" and "You dare say that to me!" and not "How dare you to say that to me!" or "You dare to say that to me!"
the question mark is not the hint that makes this a question. well I do not expect non natives to first-handly know it. the way the sentence is formulated makes it understood as a question. a VNmese might say "(những) ai dám sẽ thắng" to translate "who(ever) dares wins".
the Vietnamese sentence might be fine, but we are being asked to translate it into English. Who dares win is unnatural, ambiguous, and just wrong, whereas who dares wins is a known saying with a sightly different meaning, more correct as 'who dares, wins'. Who dares to win is grammatically correct and seems to be the better translation. Reported.
"Who dares win" is correct, idiomatic and natural English. It is and can only be a question ( "Who dares" is interrogative and "win" is an infinitive ). "To" is optional after "dare."
The declarative sentence "Who dares, wins" has two indicative, third person, singular verbs, "dares" and "wins" and, therefore, constitutes two clauses, one subordinate noun clause, "(The one) who dares," and the principal verb "wins."